論文 - パンディ　シャム　スディル

Fabrication of Nanobioengineered Interfaces Utilizing Quaternary Nanocomposite for Highly Efficient and Selective Electrochemical Biosensing of Urea 査読有り 国際誌

Krishna Kumar, Kshitij RB Singh, Ritu S. Rathour, Jay Singh, Subrato Bhattacharya, Shyam S. Pandey*

Langmuir ( American Chemical Society )   2024年09月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Nanobioengineered interfaces have gained attention owing to their small size and high surface area-to-volume ratio for utilization as a platform for highly selective and sensitive biosensing applications owing to the integration of biological molecules with engineered nanomaterials/nanocomposites. In this work, a novel Ag-complex, [(PPh3)2Ag(SCOf)]-based quaternary Ag–S–Zn–O nanocomposites (NCs), was synthesized through an environmentally-friendly process. The results revealed the formation of the NCs with an average crystallite size and particle size of 36.08 and 40.22 nm, respectively. In addition, this is the first study to utilize such NCs synthesized via a single-source precursor method, offering enhanced sensor performance due to their unique structural properties. Further, these NCs were used to fabricate a urease (Ur)/Ag–S–Zn–O NCs/ITO nanobioengineered electrode for precise and sensitive electrochemical biosensing of urea. The interfacial kinetic studies revealed quasi-reversible processes with high electron transfer rates and linear current responses, indicating efficient reaction dynamics. A high diffusion coefficient and low surface concentration suggested a fast diffusion-controlled process, affirming the electrode’s potential for rapid and sensitive urea detection. The biosensor demonstrated notable sensing properties such as high sensitivity (12.56 μA mM–1 cm–2) and a low detection limit (0.54 mM). The fabricated bioelectrode was highly selective and reproducible and demonstrated stability for up to 60 days. These results validate the potential of this nanobioengineered interface for next-generation biosensing applications, paving the way for advanced point-of-care diagnostics and real-time health monitoring.

DOI： 10.1021/acs.langmuir.4c02457

DOI： 10.1021/acs.langmuir.4c02457

High-Density, Nonvolatile, Flexible Multilevel Organic Memristor Using Multilayered Polymer Semiconductors 査読有り 国際誌

Shubham Sharma*, Manish Pandey, Shuichi Nagamatsu, Hirofumi Tanaka, Kazuto Takashima Kazuto Takashima Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu 808-0196, Japan More by Kazuto Takashima , Masakazu Nakamura, and Shyam S. Pandey*

ACS Applied Materials and Interfaces ( American Chemical Society )   16 ( 17 )   22282 - 22293   2024年04月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Nonvolatile organic memristors have emerged as promising candidates for next-generation electronics, emphasizingthe need for vertical device fabrication to attain a high density. Herein, we present a comprehensive investigation of high-performance organic memristors, fabricated in crossbar architecture with PTB7/Al-AlOx-nanocluster/PTB7 embedded between Alelectrodes. PTB7 films were fabricated using the Unidirectional Floating Film Transfer Method, enabling independent uniform filmfabrication in the Layer-by-Layer (LbL) configuration without disturbing underlying films. We examined the charge transportmechanism of our memristors using the Hubbard model highlighting the role of Al-AlOx-nanoclusters in switching-on the devices,due to the accumulation of bipolarons in the semiconducting layer. By varying the number of LbL films in the device architecture,the resistance of resistive states was systematically altered, enabling the fabrication of novel multilevel memristors. These multileveldevices exhibited excellent performance metrics, including enhanced memory density, high on−off ratio (>108), remarkable memoryretention (>105 s), high endurance (87 on−off cycles), and rapid switching (∼100 ns). Furthermore, flexible memristors werefabricated, demonstrating consistent performance even under bending conditions, with a radius of 2.78 mm for >104 bending cycles.This study not only demonstrates the fundamental understanding of charge transport in organic memristors but also introducesnovel device architectures with significant implications for high-density flexible applications.

DOI： 10.1021/acsami.4c03111

DOI： 10.1021/acsami.4c03111

その他リンク： https://pubs.acs.org/doi/10.1021/acsami.4c03111

Photophysical Characterization and Biointeractions of NIR Squaraine Dyes for in Vitro and in Vivo Bioimaging 査読有り 国際誌

Sai Kiran Mavileti, Galyna Bila, Valentyn Utka, Evgenia Bila, Tamaki Kato, Rostyslav Bilyy, Shyam S Pandey

ACS Applied Biomaterials ( American Chemical Society )   7 ( 1 )   416 - 428   2023年12月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The increasing demand for reliable near-infrared (NIR) probes exhibiting enduring fluorescence in living systems and facile compatibility with biomolecules such as peptides, antibodies or proteins is driven by the increasing use of NIR imaging in clinical diagnostics. To address this demand, a series of carboxy-functionalized unsymmetrical squaraine dyes (SQ-27, SQ-212, and SQ-215) along with non-carboxy-functionalized SQ-218 absorbing and emitting in the NIR wavelength range were designed and synthesized followed by photophysical characterization. This study focused on the impact of structural variations in the alkyl chain length, carboxy functionality positioning, and spacer chain length on dye aggregation and interaction with bovine serum albumin (BSA) as a model protein. In phosphate buffer (PB), the absorption intensity of the dyes markedly decreased accompanied by pronounced shoulders indicative of dye aggregation, and complete fluorescence quenching was seen in contrast to organic solvents. However, in the presence of BSA in PB, there was a enhancement in absorption intensity while regaining the fluorescence coupled with a remarkable increase in the intensity with increasing BSA concentrations, signifying the impact of dye–BSA interactions on preventing aggregation. Further analysis of Job’s plot unveiled a 2:1 interaction ratio between BSA and all dyes, while the binding studies revealed a robust binding affinity (Ka) in the order of 107/mol. SQ-212 and SQ-215 were further tested for their in vitro and in vivo imaging capabilities. Notably, SQ-212 demonstrated nonpermeability to cells, while SQ-215 exhibited easy penetration and prominent cytoplasmic localization in in vitro studies. Injection of the dyes into laboratory mice showcased their efficacy in visualization, displaying stable and intense fluorescence in tissues without toxicity, organ damage, or behavioral changes. Thus, SQ-212 and SQ-215 are promising candidates for imaging applications, holding potential for noninvasive cellular and diagnostic imaging as well as biomarker detection when coupled with specific vectors in living systems.

DOI： https://doi.org/10.1021/acsabm.3c00997

DOI： https://doi.org/10.1021/acsabm.3c00997

その他リンク： https://pubs.acs.org/doi/10.1021/acsabm.3c00997

Fabrication of solid-state dye-sensitized solar cells by controlled evaporation of solvents for creation of facile charge transport pathway 査読有り 国際誌

Yuki Kurokawa, Takehito Kato, Shyam S. Pandey

Physica Status Solidi-A ( Wiley )   220 ( 24 )   2300116 (1) - 2300116 (7)   2023年08月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Solid-state dye-sensitized solar cells (ss-DSSCs) based on MK-2 dye-sensitized TiO2 photoanode and the most commonly used I−/I3− redox electrolyte are successfully fabricated by the simple method of solidification of the injected liquid electrolyte under slow solvent evaporation. The use of the ionic liquid, which is solid at room temperature, and slow evaporation of solvent at low temperature is a key step for solidification toward the fabrication of ss-DSSCs. It has been demonstrated that ss-DSSCs thus fabricated not only retain about 80% of photoconversion efficiency (PCE) as compared to their liquid-state DSSCs counterpart but also maintain the device stability for more than 1000 h. PCE of the ss-DSSCs is found to increase as a function of the increasing concentration of the ionic liquid used for electrolyte preparation. In the case of ss-DSSCs with the ionic liquid concentration of 1.2 m, there is a good balance between PCE and durability leading to not only retention of about 70% of PCE as compared to its liquid-state DSSCs counterparts but also maintaining the stability of the solar cell for more than 1000 h stored at room temperature.

DOI： https://doi.org/10.1002/pssa.202300116

DOI： https://doi.org/10.1002/pssa.202300116

Kyutacar

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300116

High field-effect mobility in oriented thin films of D-A type semiconducting polymers by engineering stable interfacial system 査読有り 国際誌

Shubham Sharma Ajendra K. Vats Linjun Tang Feng Kaishan Jumpei Toyoda Shuichi Nagamatsu Yoshito Ando Masaaki Tamagawa Hirofumi Tanaka Manish Pandey Shyam S. Pandey

Chemical Engineering Journal ( Elsevier )   469   143932(1) - 143932(1)   2023年08月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Conjugated polymers (CPs) have emerged as excellent organic semiconducting materials for flexible electronic applications. CPs exhibit a notably fast carrier transport along their main π-conjugated backbone followed by inter-chain hopping compelling the need to form large and ordered domains in thin films. Therefore, the formation of larger domains, along with their orientation, is critical in controlling the electrical properties of CP-based organic electronic devices. However, controlling the molecular ordering along with the formation of large aggregates is a challenge. In this work, the unidirectional floating film transfer method (UFTM) has been utilized to prepare oriented thin films of CPs, which is a highly facile, cost-effective and material utilization efficient technique. We have demonstrated that extent and direction of molecular orientation in the fabricated thin films can be tuned along with the higher degree of aggregation. The rheological aspects, especially viscosity, play a significant role in determining molecular ordering along with the formation of these large aggregates. Active control of viscosity to achieve a stable interfacial viscous system is paramount to achieving this, resulting in a very high mobility of 12.4 cm2V−1s−1.

DOI： 10.1016/j.cej.2023.143932

DOI： 10.1016/j.cej.2023.143932

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S1385894723026633

Boosting the Performance of Organic Phototransistors Utilizing Oriented Thin‐Films of Liquid Crystalline Conjugated Polymer PBTTT C‐14 査読有り 国際誌

Sidhi G. Ramer, Kumar Vivek Gaurav, I. A. Palani, Yoshito Ando, Shyam S. Pandey, Vipul Singh

Physica Status Solidi: Rapid Research Letters ( Wiley )   25000011(1) - 25000011(8)   2025年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

To improve the organic field-effect transistor (OFET) performance, the advantages of the unidirectional floating film transfer method (UFTM) are utilized to fabricate uniaxially aligned thin film of a liquid crystalline semiconducting polymer (SCP) upon a SiO2 surface modified with a self-assembled monolayer (SAM) of alkyl-silane. We deposited the SAM of octadecyl-triethoxy silane (OTES) by spin coating onto the SiO2 gate dielectric surface to make the surface hydrophobic and promote the molecular self-assembly of aligned SCP. The electrical anisotropy of the UFTM fabricated thin films of poly [2,5-bis (3-tetradecylthiophen-2-yl) thieno [3,2-b] thiophene] (PBTTT) C-14 were studied by constructing parallel and perpendicular OFETs. Parallel OFET exhibits a mobility of 0.13 cm2 V−1sec−1, a dark on-off ratio of 2.6 × 105, and 0V Vth. Further, OFETs are utilized as organic phototransistors (OPTs) under monochromatic green light (525 nm) illumination at an intensity of 3 mWcm−2. The photosensitivity and responsivity of parallel OPT are 6.3 × 104 and 81 AW−1, respectively, which are much more pronounced compared to that of the corresponding perpendicular OPT with the photosensitivity and responsivity of 2 × 102 and 6.2 AW−1, respectively. This work contributes to the advancement of organic photodetector technology, offering valuable guidance for future device development and applications.

DOI： https://doi.org/10.1002/pssr.202500011

DOI： https://doi.org/10.1002/pssr.202500011

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssr.202500011

Implication of Surface Passivation on the In-Plane Charge Transport in the Oriented Thin Films of P3HT 査読有り 国際誌

Nisarg Hirens Purabiarao, Kumar Vivek Gaurav, Shubham Sharma, Yoshito Ando, Shyam Sudhir Pandey

Electronic Materials ( MDPI )   6 ( 2 )   6020006(1) - 6020006(14)   2025年05月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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Open AccessArticle
Implication of Surface Passivation on the In-Plane Charge Transport in the Oriented Thin Films of P3HT
by Nisarg Hirens Purabiarao,Kumar Vivek GauravORCID,Shubham Sharma,Yoshito Ando andShyam Sudhir Pandey *ORCID
Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Fukuoka 808-0196, Japan
*
Author to whom correspondence should be addressed.
Electron. Mater. 2025, 6(2), 6; https://doi.org/10.3390/electronicmat6020006
Submission received: 5 March 2025 / Revised: 22 April 2025 / Accepted: 1 May 2025 / Published: 7 May 2025
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Abstract
Optimizing charge transport in organic semiconductors is crucial for advancing next-generation optoelectronic devices. The performance of organic field-effect transistors (OFETs) is significantly influenced by the alignment of films in the channel direction and the quality of the dielectric surface, which should be uniform, smooth, and free of charge-trapping defects. Our study reports the enhancement of OFET performance using large-area, uniform, and oriented thin films of regioregular poly[3-hexylthiophene] (RR-P3HT), prepared via the Floating Film Transfer Method (FTM) on octadecyltrichlorosilane (OTS) passivated SiO2 surfaces. SiO2 surfaces inherently possess dangling bonds that act as charge traps, but these can be effectively passivated through optimized surface treatments. OTS treatment has improved the optical anisotropy of thin films and the surface wettability of SiO2. Notably, using octadecene as a solvent during OTS passivation, as opposed to toluene, resulted in a significant enhancement of charge carrier transport. Specifically, passivation with OTS-F (10 mM OTS in octadecene at 100 °C for 48 h) led to a >150 times increase in mobility and a reduction in threshold voltage compared to OTS-A (5 mM OTS in toluene for 12 h at room temperature). Under optimal conditions, these FTM-processed RR-P3HT films achieved the best device performance, with a saturated mobility (μsat) of 0.18 cm2V−1s−1.

DOI： https://doi.org/10.3390/electronicmat6020006

DOI： https://doi.org/10.3390/electronicmat6020006

その他リンク： https://www.mdpi.com/2673-3978/6/2/6

Enhancing the performance of PbS colloidal quantum dot solar cell: A computational study on absorber crystallinity and interfacial defect engineering 査読有り 国際誌

Nisarg Hirens Purabiarao, Kshitij Bhargava, Shyam S Pandey

Next Materials ( Elsevier )   8   100689(1) - 100689(9)   2025年04月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

This study utilizes the SCAPS-1D simulator to computationally investigate the effect of absorber layer crystallinity and interfacial properties on the performance of PbS colloidal quantum dot (CQD) solar cell. Crystallinity of the absorber layer is modeled by varying the defect density, while interfacial behavior is analyzed by altering the defect density at the interfaces between the electron transport layer (ETL)/PbS-TBAI, and PbS-TBAI/hole transport layer (HTL). To optimize the efficiency of the PbS-TBAI CQD solar cell, acceptor (NA) and donor doping (ND) densities were tailored in the HTL and ETL, respectively. The findings indicate that tuning these parameters is pivotal for enhancing the cell performance. Detailed analysis revealed that the cell performance is strongly influenced by the crystallinity of the PbS-TBAI absorber layer. Additionally, the results demonstrated that the ETL/PbS-TBAI interface plays a more significant role in determining cell efficiency than the PbS-TBAI/HTL interface. Moreover, optimizing the back contact metal is shown to aid in efficient hole transfer by minimizing energy losses, thereby improving overall performance. The optimized solar cell demonstrated an efficiency exceeding 19 %. These findings underscore the importance of fine-tuning key parameters to enhance the efficiency of PbS CQD solar cell.

DOI： https://doi.org/10.1016/j.nxmate.2025.100689

DOI： https://doi.org/10.1016/j.nxmate.2025.100689

その他リンク： https://www.sciencedirect.com/science/article/pii/S2949822825002072

The effect of Titanium (IV) chloride surface treatment and titanium dioxide/graphenated carbon nano-tube composite photoanode to enhance charge transport and light harvesting of bifacial dye-sensitized solar cell 査読有り 国際誌

Ismail Lawal, Suhaidi Shafie, Shyam S Pandey, Haslina Jafaar, Mohd Amrallah Mustafa, Ibrahim Onuwe Abdulmalik, Ismayadi Ismail, Mazliana Ahmad Kamarudin, Ikhwan Syafiq Mohd Noor, Fauzan Ahmad, Xinzhi Liu

Solar Energy ( Elsevier )   294   113495(1) - 113495(12)   2025年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

This study investigates a novel photoanode architecture for bifacial dye-sensitized solar cells (B-DSSCs), integrating a graphenated carbon nano-tube (g-CNT) composite with a translucent TiCl4 (T/sp) layer and TiCl4-induced compact and blocking layers. A bilayer pristine TiO2 photoanode served as the control, while the composite variants incorporated g-CNT at 0.0025–0.0500 wt% concentrations in a cascaded structure with TiO2 (T/sp). Before TiCl4 treatment, the 0.01 wt% g-CNT variant achieved a 4.8437 % power conversion efficiency (PCE), a 42.5 % increase over the control (2.7857 %). conducting TiCl4 treatment, the 0.005 wt% g-CNT composites exhibited optimal performance with a bifacial PCE of 6.4447 %, representing a 25 % enhancement over untreated variants and a 56.8 % improvement over the control. This performance improvement trend was similarly corroborated by incident photon-to-current efficiency (IPCE) measurements. The optimized photoanode demonstrated an intermediary band gap of 3.24 eV of the three variants. FESEM imagery and EDX data confirmed g-CNT incorporation, evidenced by sp2 in-plane stretching in Raman spectra and a diffraction peak at 26.2° (002) in XRD. Electrochemical analysis revealed moderate charge collection efficiency (ηcc) in untreated samples, while the presence of g-CNT enhances charge transport. TiCl4 passivation further improved ηcc, particularly in the T/sp + TiO2/0.005 wt% g-CNT composite, achieving 44.43 % (front) and 40.63 % (back) by reducing surface trap states and recombination. These findings underscore the synergistic effect of cascade-layered TiO2, g-CNT composites, and TiCl4 treatments in enhancing light absorption and charge transport for high-performance B-DSSCs.

DOI： https://doi.org/10.1016/j.solener.2025.113495

DOI： https://doi.org/10.1016/j.solener.2025.113495

その他リンク： https://www.sciencedirect.com/science/article/pii/S0038092X25002580

Synergistic Integration of Dye Molecule and Semiconducting Polymer for Near Infrared Organic Phototransistors 査読有り 国際誌

Subhajit Jana, Shubham Sharma, Radhe Shyam, Surya Prakash Singh, Shyam S Pandey, Yimin A Wu, Rajiv Prakash

Advanced Optical Materials ( Wiley )   13 ( 20 )   2402695(1) - 2402695(13)   2025年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Highly sensitive near-infrared (NIR) photodetectors are critical for biomedical applications demanding precision and performance. Organic phototransistors (OPTs) offer superior photo-sensing due to field-effect modulation. Yet, narrow bandgap organic semiconducting polymers (SCPs) are rarely used in high-performance NIR-OPTs because of low mobility and high dark off-current (DOC). Although bulk heterojunction can address these challenges, spin-coating often leads to non-uniform, randomly oriented domains. This study introduces an effective strategy: blending newly synthesized NIR-dye 2-((50-(4-(50-((4,5-bis(hexylthio)-1,3-dithiol-2-ylidene)methyl)-[2,20-bithiophen]-5-yl)-2,5-bis(2-ethylhexyl)-3,6-dioxo-2,3,5,6-tetrahydropyrrolo[3,4-c]pyrrol-1-yl)-[2,20 bithiophen]-5-yl)methylene)malononitrile (DPPCN) with poly[2,5-bis (3-tetradecylthiophen-2-yl) thieno[3,2-b]thiophene] (PBTTT), a p-type SCP with excellent charge transport properties. Then using a novel Floating Film Transfer Method (FTM) to control molecular self-assembly at the air–liquid interface, the PBTTT/DPPCN system achieves uniaxial molecular orientation (DR ≈3.29) and improved film crystallinity. OPTs made of PBTTT/DPPCN(2%) exhibit remarkable photosensitivity of 2.8 × 103 under NIR and 2.2 × 10⁴ under red light (1 mW cm−2). Optimized devices achieve high photoresponsivity of 4.82 × 103 A W−1 in NIR with EQE reaching ≈1 × 10⁷%, with even greater responsivity to red light. Improved performance is attributed to enhanced charge-transfer interaction between PBTTT and DPPCN, efficient exciton dissociation, and superior charge transport by oriented PBTTT backbones. This approach successfully delivers high-performance OPTs, advancing the potential of organic electronics for biomedical applications and beyond.

DOI： https://doi.org/10.1002/adom.202402695

DOI： https://doi.org/10.1002/adom.202402695

その他リンク： https://advanced.onlinelibrary.wiley.com/doi/full/10.1002/adom.202402695

Influence of surface passivation aiming towards enhancing the performance of organic phototransistor fabricated using oriented thin films of PFO-DBT 査読有り 国際誌

Sidhi G Ramer, Kumar Vivek Gaurav, IA Palani, Yoshito Ando, Shyam S Pandey, Vipul Singh

Synthetic Metals ( Elsevier )   312   117869(1) - 117869(8)   2025年03月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Oriented and uniform thin films of solution-processable organic semiconducting copolymer PFO-DBT were fabricated using a recently developed unidirectional floating film transfer (FTM) method and used as an active semiconductor on surface passivated Si/SiO2 as gate dielectric to fabricate organic phototransistor (OPT) in the bottom gate top contact device architecture. The influence of different passivation of SiO2 such as an ultrathin spin-coated cyclic transparent optical polymer (CYTOP) and the self-assembled monolayer of hexamethyldisilazane (HMDS) on anisotropic charge transport and device performance of OPTs have been systematically investigated. FTM-processed thin films provided good optical anisotropy in thin films and electrical anisotropy in the OPTs. With improved surface properties and enhanced anisotropies, the device showed a charge carrier mobility of 7.8 × 10-3 cm2/V-sec, on/off ratio in the order of 105, and a threshold voltage of -4V under dark conditions. OPTs fabricated in this work demonstrated photosensitivity nearly of order 104 and a corresponding responsivity of 17 A/W under the illumination of 525 nm monochromatic green light with a low power density of 0.15 mW/cm2. The results are promising for making OPTs with enhanced mobility, photosensitivity and photo-responsivity in the visible region.

DOI： https://doi.org/10.1016/j.synthmet.2025.117869

DOI： https://doi.org/10.1016/j.synthmet.2025.117869

その他リンク： https://www.sciencedirect.com/science/article/pii/S0379677925000451

High Responsivity in Near-Infrared Phototransistor With Oriented Polymer Semiconductors 査読有り 国際誌

Manish Pandey, Shubham Sharma, Shyam S Pandey, Masakazu Nakamura

IEEE Sensor Letters ( IEEE )   9 ( 4 )   1 - 4   2025年03月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Near-infrared organic phototransistors (OPTs) in bottom-gated top-contact structures are being reported using an oriented p-type diketopyrrolopyrrole-based semiconducting polymer (SCP) (DPPT-TT). Here, highly oriented DPPT-TT floating films were prepared on a liquid substrate using the unidirectional floating-film transfer method (UFTM) and then utilized as the active layer. This innovative approach exhibits a dual-orientation advantage: They align polymer chains unidirectionally, enhancing charge transport along the backbone while simultaneously promoting an edge-on molecular arrangement relative to the substrate. This combination, coupled with highly uniform thin films, facilitates efficient charge transport pathways, contributing significantly to the fabrication of high-performance OPTs. Our DPPT-TT-based OPT exhibited a high field-effect mobility of 1.5 cm2·V−1·s−1 and photoresponsivity (R) > 105 A·W−1 at an intensity of 45 μW·cm−2 under 810 nm light illumination. This exceptional performance is attributed to faster carrier transport and efficient charge collection in the oriented DPPT-TT films enabled by the UFTM.

DOI： 10.1109/LSENS.2025.3549783

DOI： 10.1109/LSENS.2025.3549783

その他リンク： https://ieeexplore.ieee.org/abstract/document/10933571

Performance of in-materio physical reservoir computing devices based on highly oriented semiconducting polymer thin films 査読有り 国際誌

Moulika Desu, Ahmet Karacali, Yuki Usami, Yuya Ishizaki-Betchaku, Shusaku Nagano, Muzhen Xu, Shyam S Pandey, Hirofumi Tanaka

Japanese Journal of Applied Physics ( IOP Publishing )   64   04SP12(1) - 04SP12(7)   2025年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Physical reservoir computing (PRC) harnesses the intrinsic nonlinear dynamics of physical systems for efficient temporal data processing, offering significant advantages in energy-efficient hardware implementation. This study explores the potential of oriented semiconducting polymer (SCP) thin films as reservoirs for PRC, focusing on two types of SCP benzo[c]cinnoline-based conjugated polymer diketopyrrolopyrrole benzo[c]cinnoline p(DPP-BZC) and regioregular poly(3-hexyl thiophene) (RR-P3HT). To enable anisotropic charge transport, uniaxially oriented thin films with edge-on molecular orientation were fabricated using the floating film transfer method. The films were electrically evaluated for anisotropic nonlinear responses, phase-shifting capabilities, and high-dimensional mapping in PRC tasks. Performance metrics, including waveform generation accuracy, were systematically investigated under varying device configurations and molecular structures. The study underscores the critical role of different conjugated polymers and their orientations in PRC performance, paving the way for developing next-generation materials for temporal signal processing and low-power intelligent hardware.

DOI： 10.35848/1347-4065/adbf9f

DOI： 10.35848/1347-4065/adbf9f

Next-generation nanobioengineered materials for micro-and nano-plastic detection 査読有り 国際誌

Kshitij RB Singh, Jay Singh, Shyam S Pandey

Current Opinion in Chemical Engineering ( Elsevier )   48   101102(1) - 101102(10)   2025年02月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Micro- and nano-plastics (MNPs) have garnered global attention as pervasive and emerging contaminants due to their potential risks to humans and the environment. Their toxicity, bioaccumulation, and oxidative stress disrupt ecosystems, demanding an urgent need for risk monitoring. A thorough understanding of the extent of the problem and the need for an amicable solution utilizing nanobioengineered materials is highly desired owing to their unique properties, such as tailored surface chemistry, specificity, and high sensitivity. These properties allow them to interact with the contaminants at the molecular level, making them suitable for MNP detection. Moreover, they have the potential to overcome challenges, such as the complex environmental matrices, data reproducibility, and inefficient sampling faced by pre-existing techniques, making them a promising tool for detecting MNPs. This review presents the importance of next-generation nanobioengineered materials for developing biosensors for MNP detection, and efforts have also been directed to enrich the awareness of the researchers working in this domain by providing innovative solutions to challenges faced by pre-existing techniques. Additionally, utilizing these materials in biosensing devices helps to attain the Sustainable Development Goals of the United Nations by bridging Nano-biotechnology and environmental science, fostering future research, and shaping policies to combat MNP pollution.

DOI： https://doi.org/10.1016/j.coche.2025.101102

DOI： https://doi.org/10.1016/j.coche.2025.101102

その他リンク： https://www.sciencedirect.com/science/article/pii/S2211339825000139

Squaraine-Peptide Conjugates as Efficient Reporters of Neutrophil Extracellular Traps-Mediated Chronic Inflammation 査読有り 国際誌

Sai Kiran Mavileti, Galyna Bila, Valentyn Utka, Rostyslav Bilyy Jr, Evgenia Bila, Elena Butoi, Shekhar Gupta, Priyanka Balyan, Tamaki Kato, Rostyslav Bilyy, Shyam S Pandey

ACS Applied Materials & Interfaces ( American Chemical Society )   17 ( 6 )   9140 - 9154   2025年02月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The excessive and uncontrolled release of neutrophil extracellular traps (NETs) is increasingly linked to the pathogenesis of various inflammatory diseases, cardiovascular disorders, and cancers. Real-time, non-invasive detection of NETs is crucial for understanding their role in disease progression and developing targeted therapies. Current NETs detection methods often lack the necessary specificity and resolution, particularly in vivo and ex vivo settings. To address this, we have developed novel near-infrared squaraine-peptide conjugates by rational molecular design as reporters of NETosis by targeting the protease activity of neutrophil elastase (NE). These self-quenching, cell-impermeable probes enable the precise real-time detection and imaging of NETs. The Förster resonance energy transfer (FRET)-based probe, Hetero-APA, demonstrated high specificity in detecting NETs in vitro and in vivo, generating strong fluorescence in NETs-rich environments. To overcome the limitations of FRET-based probes for ex vivo imaging, we designed SQ-215-NETP, a non-FRET-based probe that covalently binds to the NE. SQ-215-NETP achieved an unprecedented imaging resolution of 90 nm/pixel in human coronary thrombi, marking the first report of such high resolution with a low molecular weight probe. Additionally, SQ-215-NETP effectively detected NETs by flow cytometry. These results highlight the potential of these probes in NETosis detection, offering promising tools for enhanced diagnostics and therapeutic strategies in managing NET-mediated inflammatory diseases and cancers.

DOI： https://doi.org/10.1021/acsami.4c20658

DOI： https://doi.org/10.1021/acsami.4c20658

その他リンク： https://pubs.acs.org/doi/full/10.1021/acsami.4c20658

Maximizing solar energy harvesting: Enhancing the efficiency of bifacial dye-sensitized solar cells with Graphenated carbon nanotubes composites in multi-layered stacked photoanode 査読有り

Ismail Lawal, Suhaidi Shafie, Shyam S Pandey, Haslina Jafaar, Mohd Amrallah Mustafa, Ismayadi Ismail, Mazliana Ahmad Kamarudin, Ikhwan Syafiq Mohd Noor, Xinzhi Liu, Hussein A Alsultan, Suleiman Babani, Ibrahim Bako Abdulhamid, Nurbahirah Norddin

Optical Materials ( Elsevier )   160   116721(1) - 116721(11)   2025年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

his study inaugurally delves into optimizing bifacial dye-sensitized solar cells (DSSCs) by integrating graphene-carbon nanotubes (g-CNT) into the matrix of titanium dioxide (TiO2) for application as a mesoporous semiconductor material. TiO2 nanoparticles were synthesized using a hydrothermal method and then impregnated with g-CNT at concentrations of 0.0025 wt%, 0.0050 wt%, and 0.0100 wt%. Photoanodes were fabricated using these paste variants, and their performance was assessed. The results show that the 0.005 wt% g-CNT variant notably enhances the performance of the TiO2 cell, increasing its overall power conversion efficiency (PCE) from 3.76 % to approximately 4.53 %, representing a 20 % improvement. An innovative approach was introduced by layering a transparent TiO2 with an additional layer of the optimized composite containing the 0.005 wt% g-CNT variant. This concept …

DOI： https://doi.org/10.1016/j.optmat.2025.116721

DOI： https://doi.org/10.1016/j.optmat.2025.116721

その他リンク： https://www.sciencedirect.com/science/article/pii/S0925346725000801

Self-assembled complexes: From molecules to bioderived materials for sustainable sensing technologie 査読有り

Ravindra Pratap Singh, Shyam S Pandey, Arunadevi Natarajan, Jay Singh

Journal of Molecular Structure ( Elsevier )   1329   141414(1) - 141414(5)   2025年01月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

This special issue is focused on the development and characterization of nanosized self-assembled molecules for various sensing applications. The scope of the issue was contented and received many research and review articles, proving that the process of synchronizing chemistry/biology/material science with novel technology will end up with substances of sensing importance. The quality of the published articles in this issue is revealed from their way of interpretation, illustrative diagrams, and scientific explanation. All the articles in this special issue will upsurge the understanding and knowledge about functional materials to budding researchers.

DOI： https://doi.org/10.1016/j.molstruc.2025.141414

DOI： https://doi.org/10.1016/j.molstruc.2025.141414

その他リンク： https://www.sciencedirect.com/science/article/pii/S0022286025001036

Advances in field effect transistor based electronic devices integrated with CMOS technology for biosensing 査読有り 国際誌

Harshita Rai, Kshitij RB Singh, Arunadevi Natarajan, Shyam S Pandey

Talanta Open ( Elsevier )   11   100394(1) - 100394(12)   2024年12月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

This review article embarks on an enlightening journey through the multifaceted realm of electronic devices and their applications in biosensing, emphasizing the role of Field effect transistor (FET) based biosensors and Complementary Metal Oxide Semiconductor (CMOS) processes in biosensing device development. It begins by elucidating the foundational principles of biosensing and underscoring the crucial contribution of transducers, establishing a robust understanding of the field. The article unravels the intricate interplay between electronic biosensors and CMOS processes, offering a concise yet insightful exploration of their operational intricacies, diverse practical applications, and recent advancements. Additionally, it spotlights the pivotal role of FET-based biosensors integrated with CMOS processes in miniaturizing biosensors and thus amplifying their real-world efficacy. Moreover, the role of modern technologies, such as the Internet of Things (IoT), in recent biosensor development has been discussed. By addressing inherent challenges like sensitivity, integration, cost, and accessibility, the article underscores the vital role of biosensing technologies driven by electronic devices in wearable technology development. In addition, integrating these devices to fit with the ongoing trend of VLSI technology faces significant challenges. To overcome this aspect, sensors based on molecularly imprinted polymers (MIPs) can be the best alternative, as they will avoid utilizing bioreceptors, as it simplifies integration by reducing complexity, enhancing stability, and improving compatibility with CMOS processes. Hence, this review's distinct contribution lies in its comprehensive approach, shedding light on how biosensing technologies, underpinned by electronic devices such as FETs and CMOS processes, offer solutions for realizing modern-day devices.

DOI： https://doi.org/10.1016/j.talo.2024.100394

DOI： https://doi.org/10.1016/j.talo.2024.100394

その他リンク： https://www.sciencedirect.com/science/article/pii/S2666831924001085

Simultaneous Control of Self-Assembly and Photon Harvesting Window in NIR-Sensitive Squaraine Dyes for Next-Generation Bifacial Solar Cells 査読有り

Safalmani Pradhan, Yuki Kurokawa, Shekhar Gupta, Kshitij RB Singh, Shyam S Pandey

ACS Applied Energy Materials ( American Chemical Society )   7 ( 14 )   12004 - 12015   2024年12月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Sensitizers utilized in dye-sensitized solar cells (DSSCs) play a crucial role in solar energy harvesting, and their capability to harvest photons in the wide-wavelength region encompassing visible to near-infrared regions is highly desirable. In addition to this, electron injection along with self-assembly of the dyes also plays a rather important role, and therefore their precise control is highly desirable and challenging too. This study deals with the molecular engineering approaches directed toward the molecular design and synthesis of two unsymmetrical squaraine dyes (SQ-260 and SQ-261), introducing extended π-conjugated moieties in the dye molecular framework of the reference dye SQ-258. Further, the bifacial DSSCs were fabricated using the dyes, and their photophysical and photovoltaic properties were investigated comprehensively. SQ-258, bearing a typical unsymmetrical squaraine dye structure …

DOI： https://doi.org/10.1021/acsaem.4c02497

DOI： https://doi.org/10.1021/acsaem.4c02497

Comprehensive perspective of sustainable nanostructured metal and metal oxide towards agriculture utility for precision farming 査読有り

Pooja Singh, Vanya Nayak, Ranjana Verma, Arunadevi Natarajan, Jay Singh, Shyam S Pandey, Kshitij RB Singh

Biocatalysis and Agricultural Biotechnology ( Elsevier )   62   103457(1) - 103457(26)   2024年12月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The growing advancements in science and technology have brought forward a new domain with the potential to manipulate structures at nano dimensions, termed nanotechnology. Nanotechnology uses materials whose dimensions lie between 1 and 100 nm, which offers them excellent properties and a high surface-to-volume ratio that further enriches it with enormous attention in various domains. Apart from the biomedical and environmental domains, agriculture has also highly utilized nanotechnology in past decades as it carries the global burden of fulfilling food demands and boosting a country's economy. Therefore, developing and enhancing agriculture and its products have become the primary needs of researchers and the government. Moreover, metal-based nanoparticles are highly preferred in the agricultural sector because they can be easily synthesized, readily taken by plants from soil and water, act as excellent antimicrobials, pesticides, and fertilizers, and are also highly used in genetic engineering. Moreover, to reduce their toxicity, biogenic metal-based nanoparticles are synthesized utilizing extracts of plant parts, microorganisms, biomolecules, nutrients, etc. In this article, a systematic review was deliberated by providing pathways to the budding researchers, starting from various types of synthesis of biogenic nanoparticles, factors influencing the formation, and their application in various agricultural sectors. The integration of nanotechnology in agriculture, specifically through the use of biogenic metal-based nanoparticles, addresses key Sustainable Development Goals (SDGs) such as Goal 2: Zero Hunger by enhancing food production and security, Goal 12: Responsible Consumption and Production by optimizing resource use, and Goal 15: Life on Land by promoting sustainable farming practices that minimize environmental impact. Hence, nanoparticle-assisted delivery to plants will lead to precision farming and articulate several challenges in traditional agriculture.

DOI： https://doi.org/10.1016/j.bcab.2024.103457

DOI： https://doi.org/10.1016/j.bcab.2024.103457

その他リンク： https://www.sciencedirect.com/science/article/pii/S1878818124004419

A label-free liquid–crystal-droplet based optical sensing platform for the detection of Neisseria gonorrhoeae 査読有り

Rohit Kumar, Gajjala Sumana, Seema Sood, Shyam S Pandey, Hirofumi Tanaka

Journal of Molecular Liquids ( Elsevier )   415 ( Part(B) )   126410(1) - 126410(9)   2024年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

An oligonucleotide decorated liquid crystal (LC) droplet platform was studied for the detection of sexually transmitted disease (STD) caused by bacterium Neisseria gonorrhoeae. Homeotropically aligned nematic LC droplets were patterned on the silane modified glass plates and were utilized as sensing platform using an oligonucleotide probe (ssDNAprobe) sequence specific for N. gonorrhoeae. The developed LC-droplets platform could detect the synthetic complementary DNA (ssDNAtarget) and genomic DNA of N. gonorrhoeae with dark polarizing optical microscopy (POM) images of homeotropic LC alignment up to the lowest detectable limit of 10 pM and 50 pM, respectively. The DNA hybridization event was further monitored by zeta potential (ζ) measurement of LC droplets using dynamic light scattering technique to understand the sensing mechanism of ssDNAprobe hybridization with ssDNAtarget. The zeta potential response showed a linear relationship to ssDNAtarget over a concentration range of 10 pM to 100 nM and a limit of detection of 10 pM, which is nearly close to limit of detection (LOD) obtained with LC optical response measurement. These results indicated a similar kind of sensing mechanism with LC-droplets in both aqueous medium as well as on a glass substrate. The specificity of the LC droplet platform was investigated with various levels of mismatched synthetic DNA sequences and non-specific genomic DNA isolated from other bacteria. The homeotropic LC optical response with genomic DNA of N. gonorrhoeae in the presence of potential interferents showed that LC-droplet platform is highly selective for N. gonorrhoeae, suggesting a simple, rapid and reliable label-free detection platform.

DOI： https://doi.org/10.1016/j.molliq.2024.126410

DOI： https://doi.org/10.1016/j.molliq.2024.126410

その他リンク： https://www.sciencedirect.com/science/article/pii/S0167732224024693

A bio-nano-engineered platform fabricated from cerium oxide-carbon nanoparticles stabilized with chitosan for label-free sensing of a lung cancer biomarker 査読有り

Upendra Kumar Mishra, Saurabh Srivastava, Kshitij RB Singh, Atul Kumar, Vivekanand Singh, Devendra P Mishra, Vishal Singh Chandel, Jay Singh, Shyam S Pandey

Analytical Methods ( RSC )   17   349 - 359   2024年11月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Herein, we report a label-free cancer biosensor designed for carcinoembryonic antigen (CEA) detection using a nanohybrid comprising CeO2 nanoparticles, carbon nanoparticles (CNPs), and chitosan (Ch). CeO2 nanoparticles were prepared using a simple green synthesis process. A thin film of the CeO2-CNPs-Ch nanohybrid was formed on indium tin oxide (ITO)-coated glass plates that endowed a high surface area, excellent stability, and good adsorption for the efficient loading of CEA antibodies. Quantitative and selective determination of CEA antigen was achieved by immobilizing monoclonal CEA antibodies (anti-CEA) on the CeO2-CNPs-Ch/ITO platform. The electrochemical response of the anti-CEA/CeO2-CNPs-Ch/ITO immunoelectrode was evaluated in a label-free immunoassay format using differential pulse voltammetry (DPV). The response studies of immunoelectrodes indicated wider linearity with

DOI： https://doi.org/10.1039/D4AY01535E

DOI： https://doi.org/10.1039/D4AY01535E

Black phosphorene: A versatile allotrope revolutionizing environmental, energy, and biomedical applications 査読有り 国際誌

oumya Ranjan Mishra, Vishal Gadore, Vishwajit Chavda, Subhasree Panda, Saptarshi Roy, Pooja Sahoo, Lipi Pradhan, Harshita Rai, Shyam S Pandey, Md Ahmaruzzaman

Coordination Chemistry Reviews ( Elsevier )   524   216345(1) - 216345(1)   2024年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Black phosphorene (BP), an exciting allotrope of phosphorus, has sparked widespread attention owing to its unique physicochemical characteristics and numerous potentials in the environmental, energy, and biological sectors. The current review delves further into BP, concentrating on its layered structure, unusual features, and broad applications. Methods of synthesis of BP, such as liquid exfoliation, chemical vapor deposition, and mechanical exfoliation, are reviewed, and characterization procedures critical to ensuring the quality of BP are described. Its anisotropic mechanical, electrical, and optical properties are investigated using insights gained from its hexagonal lattice atomic structure and puckered layers. In environmental contexts, BP shows potential for water purification due to its strong adsorption and degradation capabilities against various contaminants, including dyes, medicines, pesticides, heavy metals, and organic compounds. Its potential in environmental sensing is also emphasized, notably for detecting gasses, heavy metals, and pollutants. Moving on to energy applications, BP is used in batteries, supercapacitors, and hydrogen generation, where its unique electrical and structural properties improve energy storage and conversion efficiency. BP improves medication delivery systems in biomedical applications by providing biocompatibility and customizable delivery capabilities. Furthermore, its biological imaging and diagnostics applications are reviewed, focusing on optical properties and contrast enhancement capabilities. Nonetheless, despite BP's significant potential, serious hurdles persist. Issues including stability under ambient settings, large-scale synthesis limits, and biocompatibility difficulties require resolution for more considerable practical use. The paper concludes by exploring future challenges and solutions to motivate readers. In summary, BP stands as a flexible material prepared to drive innovation in environmental, energy, and biological applications, although attaining its revolutionary influence will depend on overcoming present technological, scientific, and scaling limitations.

DOI： https://doi.org/10.1016/j.ccr.2024.216345

DOI： https://doi.org/10.1016/j.ccr.2024.216345

Role of Si and SiO2 in optoelectronic device fabrication 査読有り 国際誌

Harshita Rai, Kshitij RB Singh, Shyam S Pandey, Arunadevi Natarajan

Journal of Molecular Structure ( Elsevier )   1316   138994 (1) - 138994 (9)   2024年11月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Silicon and its oxide deliver a dextrous way for engineering the successors of optoelectronic/photonic devices, by integrating fabrication techniques with heterostructured material possessing tuneable properties. Besides comprehensive knowledge, a collection of functional materials with device fabrication should be amplified. In general, silicon-based allied compounds can co-form with other materials like polymers, nanometal oxides, and organic/inorganic hybrid materials to deliver multiple electronic characteristics. A noteworthy and excellent performance of Si and its oxide secures a prominent position in the realm of the optoelectronics field. This study deliberates an exhaustive overview of advances in fabrication strategies, characteristics, Si/SiO2-based optoelectronic devices, and new materials used in this field. Additionally, this investigation spotlights the potential of Si/SiO2 in accentuating diverse …

DOI： https://doi.org/10.1016/j.molstruc.2024.138994

DOI： https://doi.org/10.1016/j.molstruc.2024.138994

Polarized polymer light-emitting electrochemical cells using polyfluorene and polycaprolactone blend film by floating-film transfer method 査読有り 国際誌

Towa Nagao, Masaki Yasukawa, Shyam S. Pandey, Masahiro Misaki and Shuichi Nagamatsu

Japanese Journal of Applied Physics ( IOP Publishing )   63 ( 11 )   11SP08-1 - 11SP08-5   2024年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Sandwich-type structured polarized Polymer Light-emitting Electrochemical Cells (PLECs) of poly (9,9-dioctylfluorene) (PFO) successfully fabricated by a combination of floating-film transfer method (FTM) and Post-blending ionic liquid (IL) procedure. An ion-solvating polymer, polycaprolactone (PCL), was blended in PFO to improve IL penetration. The PFO:PCL film showed clear optical dichroism due to the PFO backbone orientation. The IL, 1-Ethyl-3-methylimidazolium (trifluoromethylsulfonyl)imide (EMIm-TFSI), easily post-blended into the PFO:PCL blend FTM film without disordering PFO backbone orientation. The fabricated thickness-varied PLECs with ITO anode and aluminum cathode demonstrated distinct anisotropy, whole device area emission, and low turn-on voltage compared to PLEDs.

DOI： 10.35848/1347-4065/ad8ed2

DOI： 10.35848/1347-4065/ad8ed2

Full View Nanobioengineered Al2O3 Core–Shell Nanoparticle Preparation Using Bauhinia Variegate Plant Extract for Efficient Photocatalysis and Electrochemical Sensing 査読有り 国際誌

Kshitij RB Singh, Pooja Singh, Jay Singh, Shyam S Pandey

ACS Applied Bio Materials ( American Chemical Society )   7 ( 11 )   7646 - 7658   2024年10月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Core–shell-based nanomaterials have garnered considerable attention in the recent past not only in catalytic applications but also in their potentiality in selective and efficient sensing. Present research reports the first and successful biosynthesis of the core (c-Al2O3)–shell nanoparticles (NPs) using Bauhinia variegate blossom extract as reducing and capping agents. The synthesized c-Al2O3 NPs were characterized and utilized to fabricate nanobioengineered electrodes on indium tin oxide (ITO) substrates via electrophoretic deposition. Electrochemical analysis, including cyclic voltammetry and differential pulse voltammetry, revealed quasi-reversible processes with high electron-transfer rates (Ks = 0.66 s–1) and a diffusion coefficient (D = 5.84 × 10–2 cm2 s–1). The electrode exhibited a very high sensitivity (23.44 μA μM–1 cm–2) and a low detection limit (0.463 μM) for sodium azide (NaN3) over two linear ranges of 1–6 and 8–20 μM. Additionally, c-Al2O3 NPs demonstrated the effective photocatalytic degradation of crystal violet dye under visible light, following pseudo-first-order kinetics. The fabricated electrode showed excellent selectivity, stability, and reproducibility, highlighting its potential for environmental monitoring and clinical diagnostics.

DOI： https://doi.org/10.1021/acsabm.4c01213

DOI： https://doi.org/10.1021/acsabm.4c01213

Chemical sensor technologies for sustainable development: recent advances, classification, and environmental monitoring 査読有り

Abel Inobeme, Arunadevi Natarajan, Safalmani Pradhan, Charles Oluwaseun Adetunji, Alexander Ikechukwu Ajai, Jonathan Inobeme, Mathew John Tsado, John Olusanya Jacob, Shyam S Pandey, Kshitij RB Singh, Jay Singh

Advanced Sensor Research ( Wiley )   3 ( 12 )   2400066 (1) - 2400066 (19)   2024年10月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

One of the significant issues of concern in recent times is detecting, quantifying, and monitoring various chemical contaminants in the environment. Numerous inorganic and organic substances are discharged into the environment from various anthropogenic activities, thereby polluting the ecosystems' air, water, soil, and other components. These contaminants have been documented to have deleterious effects on humans, animals, and the environment. Therefore, the need for monitoring and continual quantification of the contents of these contaminants in various environmental matrices becomes paramount. Many diverse sensors are fabricated for multiple utilizations, including liquids and gas sensors, wireless sensors, electronic tongues, and noses for detecting volatile airborne substances, pollutants, and effluents. This review focuses on cutting-edge technology used in chemical sensors for environmental protection and sustainable development. It also discusses the fabrication and development of chemical sensors and their working principles. In addition, highlights about the applications of chemical sensors in environmental monitoring are also elaborated. This review article discusses emerging sensor technologies and their application in ecological monitoring. Further, the recognition of chemical warfare agents and homeland security applications with the help of bioelectronic nose and tongue is discussed. Finally, some challenges associated with chemical sensors and future trends are also attempted.

DOI： https://doi.org/10.1002/adsr.202400066

DOI： https://doi.org/10.1002/adsr.202400066

Scattering layers for Titanium dioxide and Tin dioxide Dye-sensitized solar cells with Pandan leaf as a natural sensitizer 査読有り 国際誌

Azwar Haya, Novriany Amaliyah, Asraidi Sakka, Shyam S. Pandey

Journal of Sustainable Development of Energy, Water and Environment Systems ( Međunarodni centar za održivi razvoj, energetike, voda i okoliša )   12 ( 3 )   1 - ９   2024年09月

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Dye-sensitized solar cell with a scattering layer as a light mobility enhancer has been fabricated in this work. The cells were fabricated with two types of semiconductor materials which are Titanium dioxide and Tin dioxide. Natural sensitizer from Pandan leaves was also used as an electron generator combined with liquid electrolyte redox couple Iodide/Tri-Iodide. The photovoltaic performance was measured with four types of semiconductor configurations. It was Titanium dioxide only, Titanium dioxide with scattering layer, Tin dioxide only and Tin dioxide with scattering layer. Pandan dyes have higher photovoltaic performance when fabricated with scattering layers in both semiconductor cells. The scattering layer has boosted the light management inside the photo-anode film and increased the Photo-conversion efficiency. Photo-conversion efficiency parameters such as short-circuit current and open circuit voltage were monitored to improve compared to cells without the scattering layer. Higher electron injection were contributed from the increase of light path on photo-anode film with scattering layers. The incident photon-to-current efficiency graph confirmed that the cells with Titanium dioxide with scattering layer had a higher photon-to-current density than the cells with Tin dioxide only on 300 to 500 nm. The incident photon-to-current efficiency of the device with Tin dioxide with scattering layer was higher than that of the device with Tin dioxide only in the wavelength range of 300 to 700 nm, the dominant effect of the scattering layer was found to affect more in Tin dioxide than Titanium dioxide semiconductors on low to high wavelength of the …

NIR-Sensitive Squaraine Dye—Peptide Conjugate for Trypsin Fluorogenic Detection 査読有り 国際誌

Priyanka Balyan, Shekhar Gupta, Sai Kiran Mavileti, Shyam S Pandey, Tamaki Kato

Biosensors ( MDPI )   14 ( 10 )   458(1) - 458(14)   2024年09月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Trypsin enzyme has gained recognition as a potential biomarker in several tumors, such as colorectal, gastric, and pancreatic cancer, highlighting its importance in disease diagnosis. In response to the demand for rapid, cost-effective, and real-time detection methods, we present an innovative strategy utilizing the design and synthesis of NIR-sensitive dye–peptide conjugate (SQ-3 PC) for the sensitive and selective monitoring of trypsin activity by fluorescence ON/OFF sensing. The current research deals with the design and synthesis of three unsymmetrical squaraine dyes SQ-1, SQ-2, and SQ-3 along with a dye–peptide conjugate SQ-3-PC as a trypsin-specific probe followed by their photophysical characterizations. The absorption spectral investigation conducted on both the dye alone and its corresponding dye–peptide conjugates in water, utilizing SQ-3 and SQ-3 PC respectively, reveals enhanced dye aggregation and pronounced fluorescence quenching compared to observations in DMSO solution. The absorption spectral investigation conducted on dye only and corresponding dye–peptide conjugates in water utilizing SQ-3 and SQ-3 PC, respectively, reveals not only the enhanced dye aggregation but also pronounced fluorescence quenching compared to that observed in the DMSO solution. The trypsin-specific probe SQ-3 PC demonstrated a fluorescence quenching efficiency of 61.8% in water attributed to the combined effect of aggregation-induced quenching (AIQ) and fluorescence resonance energy transfer (FRET). FRET was found to be dominant over AIQ. The trypsin-mediated hydrolysis of SQ-3 PC led to a rapid and efficient recovery of quenched fluorescence (5-fold increase in 30 min). Concentration-dependent changes in the fluorescence at the emission maximum of the dyes reveal that SQ-3 PC works as a trypsin enzyme-specific fluorescence biosensor with linearity up to 30 nM along with the limit of detection and limit of quantification of 1.07 nM and 3.25 nM, respectively.

DOI： 10.3390/bios14100458

DOI： 10.3390/bios14100458

Enhancing Optoelectronic Anisotropy in Highly Oriented Thin Films by Fluorine Substitution in Novel Semiconducting Polymers 査読有り 国際誌

Shubham Sharma, Moulika Desu, Guan-Lin Chen, Kai-Wei Tseng, Kumar Vivek Gaurav, Zhe-Yu Liu, Kuang-Hao Cheng, Safalmani Pradhan, Palraj Ranganathan, Pang-Hsiao Liu, Xiang-Ling Chiu, Hirofumi Tanaka, Jyh-Chien Chen, Chin-Ti Chen, Chi-An Dai, Leeyih Wang, Shyam S Pandey

ACS Applied Materials & Interfaces ( American Chemical Society )   16 ( 38 )   51229 - 51240   2024年09月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The recent past has witnessed remarkable progress in organic electronics, driven by the quest for flexible, lightweight, and cost-effective electronic devices. Semiconducting polymers (SCPs) have emerged as key materials in this field, offering unique electronic and optoelectronic properties along with mechanical flexibility. This study focuses on designing, synthesizing, and utilizing novel donor–acceptor (D–A) copolymer-based SCPs introducing a difluorothiophene moiety in the polymeric backbone. The importance of fluorine substitution for backbone planarity was verified by density functional theory calculations, comparing it with a nonfluorine substituted counterpart. Through the Unidirectional Floating Film Transfer Method (UFTM), we fabricated highly oriented thin films, resulting in increased optical anisotropy with dichroic ratios reaching 19.3 in PC20-FT thin films, one of the highest optical anisotropy observed for solution processable SCP thin films. X-ray diffraction and atomic force microscopy results validated the increase in the crystallinity and domain size with the increasing alkyl chain length. Finally, we elucidate these findings in the context of electrical applications by fabricating organic field-effect transistors revealing anisotropic charge transport achieving a promising mobility of 1.24 cm2V–1s–1 and mobility anisotropy of 39.5. This study offers insights into the design principles and performance optimization of SCP-based devices, paving the way for advancements in plastic electronics.

DOI： https://doi.org/10.1021/acsami.4c08566

DOI： https://doi.org/10.1021/acsami.4c08566

その他リンク： https://pubs.acs.org/doi/full/10.1021/acsami.4c08566

Smart Alginate Nanomaterials: Revolutionizing Food Across Delivery, Preservation, Packaging, Safety, and Waste Upcycling 査読有り 国際誌

Shweta Rathee, Kshitij RB Singh, Sadhucharan Mallick, Jay Singh, Shyam S. Pandey, Ankur Ojha, Ravindra Pratap Singh

Carbohydrate Polymer Technologies and Applications ( Elsevier )   2024年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

As the global population grows, the demand for safe food security aligned with sustainable development objectives becomes increasingly critical. This review delves into the innovative design techniques of stimuli-responsive smart alginate nanomaterials. It focuses on smart alginate hybrid nanomaterials and their nanocomposites that react to external stimuli. pH-responsive smart alginate hybrid nanomaterials are effectively utilized for the targeted delivery of bioactive components. Conversely, pH, temperature, specific analytes, and ionic strength-responsive smart alginate nanocomposites have food preservation, packaging, safety, and waste upcycling applications. This paper provides an in-depth examination of recent advancements in pH-responsive smart alginate hybrid nanomaterials, emphasizing targeted distribution systems, including nanoparticles, nanoliposome complexes, high internal phase Pickering emulsions, emulgels, nanogels, nanobioaerogels, and electrospun nanofibers. Moreover, the review highlights how smart alginate nanocomposites contribute to sustainable food preservation and upcycling of food waste, enhancing food safety. Detailed discussions on commercialization regulations underscore the importance of regulatory compliance and safety in deploying these advanced materials.

DOI： https://doi.org/10.1016/j.carpta.2024.100568

DOI： https://doi.org/10.1016/j.carpta.2024.100568

その他リンク： https://www.sciencedirect.com/science/article/pii/S2666893924001488?via%3Dihub

Study on the charge transport behaviour of mxene-polymer nanocomposite-based self-assembled floating films at the air-liquid interface 査読有り 国際誌

Radhe Shyam, Shubham Sharma, Shyam S Pandey, Takaaki Manaka, Rajiv Prakash

Materials Today Electronics ( Elsevier )   9   100112(1) - 100112(11)   2024年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

This study explores the fabrication and charge transport behavior of MXene-polymer nanocomposite-based self-assembled floating films at the air-liquid interface. Utilizing ultrasonic dispersion of MXene nanosheets was integrated into a DPP-TTT polymer matrix, significantly enhancing the alignment and crystallization of the polymer chains. The films were fabricated using a unidirectional floating film transfer method (UFTM), which proved to be both simple and cost-effective. UV–visible and grazing incidence X-ray diffraction (GIXD) analyses confirmed increased π–π stacking and improved structural arrangement within the nanocomposites. Organic field-effect transistors (OFETs) fabricated from these films demonstrated that a 3% MXene inclusion resulted in the highest mobility, measuring 3.1 cm2V-1s-1 with an on-off ratio in the order of 104, compared to 1.3 cm2V-1s-1 in pristine DPP-TTT films

DOI： https://doi.org/10.1016/j.mtelec.2024.100112

DOI： https://doi.org/10.1016/j.mtelec.2024.100112

Probing heavy metals in tropospheric particulate matter – An approach towards sustainability 査読有り 国際誌

Abel Inobeme, Arunadevi Natarajan, Safalmani Pradhan, Charles Oluwaseun Adetunji, Ariola Devolli, Chetan Chauhan, John Tsado Mathew, Jonathan Inobeme, Kaushik Pal, Kshitij RB Singh, Shyam S. Pandey*

Journal of Molecular Liquids ( Elsevier )   412   125822(1) - 125822(13)   2024年08月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Various organic and inorganic contaminants are increasingly found in the atmosphere due to several anthropogenic sources of alarming concern. Amongst the various classes of pollutants, heavy metals (HMs) have drawn global attention due to their bioaccumulation and biomagnification potential in cellular and sub-cellular structures of living organisms. In comparison to other media of dispersion of HMs, the mechanism involved in particulate matter (PM) in the atmosphere makes it easier for the transport of HMs over long distances at a global and regional scale due to the non-confinement of air masses. The transport of HMs through atmospheric PM requires close assessment and monitoring. At present, there is limited literature focusing on heavy metals in aerosols and dust. Most of the available studies have emphasized heavy metals in soil and water. The current review comprehensively highlights the various aspects of HMs including the sources, recent trends, and investigation models explored for the assessment and monitoring of HMs in PM and atmospheric aerosols, which will further help in achieving sustainable environmental monitoring aspects more precisely.

DOI： 10.1016/j.molliq.2024.125822

DOI： 10.1016/j.molliq.2024.125822

その他リンク： https://www.sciencedirect.com/science/article/pii/S0167732224018816?via%3Dihub

Study on the charge transport behaviour of MXene- polymer nanocomposite-based self-assembled floating films at the air-liquid interface 査読有り 国際誌

Radhe Shyam, Shubham Sharma, Shyam S. Pandey, Takaaki Manaka, Rajiv Prakash

Materials Today Electronics ( Elsevier )   9   100112(1) - 100112(11)   2024年08月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）

This study explores the fabrication and charge transport behavior of MXene-polymer nanocomposite-based self-assembled floating films at the air-liquid interface. Utilizing ultrasonic dispersion of MXene nanosheets was integrated into a DPP-TTT polymer matrix, significantly enhancing the alignment and crystallization of the polymer chains. The films were fabricated using a unidirectional floating film transfer method (UFTM), which proved to be both simple and cost-effective. UV–visible and grazing incidence X-ray diffraction (GIXD) analyses confirmed increased π–π stacking and improved structural arrangement within the nanocomposites. Organic field-effect transistors (OFETs) fabricated from these films demonstrated that a 3% MXene inclusion resulted in the highest mobility, measuring 3.1 cm2V-1s-1 with an on-off ratio in the order of 104, compared to 1.3 cm2V-1s-1 in pristine DPP-TTT films. However, further increases in MXene content reduced mobility, emphasizing the importance of precise compositional tunin

DOI： 10.1016/j.mtelec.2024.100112

DOI： 10.1016/j.mtelec.2024.100112

その他リンク： https://www.sciencedirect.com/science/article/pii/S277294942400024X?via%3Dihub

Synthesis and Characterization of Multifunctional Symmetrical Squaraine Dyes for Molecular Photovoltaics by Terminal Alkyl Chain Modifications 査読有り 国際誌

Kota Mori, Yuki Kurokawa and Shyam S. Pandey*

Colorants ( MDPI )   3 ( 3 )   198 - 216   2024年07月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Novel far-red sensitive symmetric squaraine (SQ) dyes with terminal alkyl chain modifications were designed, synthesized, and characterized, aiming towards imparting multifunctionalities such as photosensitization, dye aggregation prevention, and source of electrolyte components. The dye sensitizer SQ-80 with alkyl chain terminal modifications consisting of 1-methylimidazolium iodide was designed and synthesized as a new dye sensitizer for DSSCs based on symmetric SQ-4 without any terminal modification used as reference. Upon adsorption on the mesoporous TiO2 surface, SQ-80 demonstrated reduced dye aggregation and stronger binding to the TiO2 surface, leading to enhanced durability of DSSCs. Apart from the most common photosensitization behavior, the newly designed dye demonstrated multifunctionalities such as aggregation prevention and electrolyte functionality, utilizing iodine-based redox electrolytes in the presence and absence of I2 and LiI additives. In the absence of LiI and I2, a mixture of SQ-77 with alkyl chain terminal modifications consisting of iodide and SQ-80 demonstrated a photoconversion efficiency of 1.54% under simulated solar irradiation, which was about six times higher compared with the reference dye SQ-4 (0.24%) (having no alkyl chain terminal modification).

DOI： 10.3390/colorants3030014

DOI： 10.3390/colorants3030014

Kyutacar

その他リンク： https://www.mdpi.com/2079-6447/3/3/14

Synthesis and advances of smart heteroatom-sited coatings for anticorrosion applications 査読有り

M. Swathika, Sharmila Chandran, Kshitij RB Singh, Ravindra Pratap Singh, Shyam S. Pandey, Arunadevi Natarajan

Journal of the Taiwan Institute of Chemical Engineers ( Elsevier )   105639(1) - 105639(14)   2024年07月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Highlights
•
Novel coating material for bore water, soil, and bacterial corrosion.

•
A microphotograph of steel substrate immersed in bore water and soil reveals the anticorrosion behavior.

•
Early-stage recognition of corrosion with highly pigmented metal oxides.

•
Highest anticorrosive property was shown by epoxy-CoO nanomaterial.

DOI： 10.1016/j.jtice.2024.105639

DOI： 10.1016/j.jtice.2024.105639

Developing In2S3 upon Modified MgTiO3 Anchored on Nitrogen-doped CNT for Sustainable Sensing and Removal of Toxic Insecticide Clothianidin 査読有り 国際誌

Soumya Ranjan Mishra, Vishal Gadore, Kshitij RB Singh, Shyam S. Pandey, Md. Ahmaruzzaman

Environmental Research ( Elsevier )   259   119435(1) - 119435(23)   2024年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Herein, the study introduces a novel bifunctional In2S3/MgTiO3/TiO2@N-CNT (IMTNC) nanocomposite, which is poised to revolutionize the detection and removal of clothianidin (CLD) from aquatic environments by synergistic adsorption and photodegradation. Confirmation of the material’s synthesis was done using structural, optical, morphological, and chemical characterizations. An outstanding sensitivity of 2.168 μA/nM.cm2 with a linear range of 4–100 nM and a LOD of 0.04 nM, along with an exceptional elimination efficiency of 98.06 ± 0.84% for about 10 ppm CLD within 18 min was demonstrated by the IMTNC nanocomposite. Extensive studies were carried out to appraise the material’s effectiveness in the presence of various interfering species, such as cations, anions, organic compounds, and different water matrices, and a comprehensive assessment of its stability throughout several cycles was made. Response Surface Methodology (RSM) study was used to determine the ideal removal conditions for improved performance. In addition, the catalytic performance in removing various other pollutants was also analyzed. Adding In2S3 and developing N-doped Carbon Nanotubes (N-CNT) increased conductivity and higher electrochemical sensing skills, improving charge transfer and increasing photocatalytic activity. This research underscores the potential of the IMTNC nanocomposite as a promising candidate for advanced environmental sensing and remediation applications.

DOI： 10.1016/j.envres.2024.119435

DOI： 10.1016/j.envres.2024.119435

その他リンク： https://www.sciencedirect.com/science/article/pii/S0013935124013409?via%3Dihub

Role of Si and SiO2 in Optoelectronic Device Fabrication 査読有り 国際誌

Harshita Rai , Kshitij RB Singh , Shyam S. Pandey, Arunadevi Natarajan

Journal of Molecular Structure ( Elsevier )   1316   138994(1) - 138994(9   2024年06月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Silicon and its oxide deliver a dextrous way for engineering the successors of optoelectronic/photonic devices, by integrating fabrication techniques with heterostructured material possessing tuneable properties. Besides comprehensive knowledge, a collection of functional materials with device fabrication should be amplified. In general, silicon-based allied compounds can co-form with other materials like polymers, nanometal oxides, and organic/inorganic hybrid materials to deliver multiple electronic characteristics. A noteworthy and excellent performance of Si and its oxide secures a prominent position in the realm of the optoelectronics field. This study deliberates an exhaustive overview of advances in fabrication strategies, characteristics, Si/SiO2-based optoelectronic devices, and new materials used in this field. Additionally, this investigation spotlights the potential of Si/SiO2 in accentuating diverse applications like light-emitting diodes, solar cells, photodiodes, and phototransistors. In brief, this article will expose novel pathways of research and peregrination in this mushrooming field.

DOI： 10.1016/j.molstruc.2024.138994

DOI： 10.1016/j.molstruc.2024.138994

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S0022286024015126?via%3Dihub

Advancing dye-sensitized solar cell performance with bifacial illumination: A novel Stack Formation Framework approach 査読有り

Hussein A. AlSultan, Suhaidi Shafie, Mohd Nizar Hamidon, Ismayadi Ismail, Shyam S. Pandey, Fauzan Ahmad

Optical Materials ( Elsevier )   153   115535(1) - 115535(10)   2024年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Dye-sensitized solar cells (DSSCs) are considered to be one of the promising photovoltaic devices in terms of low cost, low toxicity, and versatility. However, the issue of low power conversion efficiency (PCE) is still a main issue of those devices, especially in low light harvesting and the issue of electron–hole recombination that hinders the PCE of the device. This study aims to enhance the PCE by maximizing the light-harvesting without sacrificing the electron–hole separation by a novel approach of the Stack Formation Framework (SFF) for multi-layered Titanium Dioxide (TiO
) photoanodes in DSSCs by integrating bifacial illumination capabilities. The SFF method, leveraging both commercial and synthesized TiO
pastes, now considers light absorption from both the front and rear sides of the device, aiming to harness the full potential of ambient light sources. Comparative analyses under varying illumination conditions reveal the T/sp-P25-T/sp (TPT) configuration’s superior efficiency (6.1%) and (3.8%) PCE in front and back respectively, with a notable increase in overall theoretical photocurrent (J
) to (15.99 mA) and (9.32 mA) in front and back illumination respectively. When both sides are utilized using a reflective mirror, the PCE reaches (9.9%). This work underscores the potential of bifacial DSSCs in maximizing energy capture and conversion, setting a new benchmark for photoanode performance in photovoltaic applications.

DOI： 10.1016/j.optmat.2024.115535

DOI： 10.1016/j.optmat.2024.115535

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S0925346724007183?via%3Dihub

Clarifying the Dominant Role of Crystallinity and Molecular Orientation in Differently Processed Thin Films of Regioregular Poly(3-hexylthiophene) 査読有り 国際誌

Kumar Vivek Gaurav, Harshita Rai, Kshitij RB Singh, Shubham Sharma,Yoshito Ando, and Shyam S. Pandey*

Micromachine ( MDPI )   15 ( 6 )   677(1) - 677(16)   2024年05月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Conjugated polymers (CPs) offer the potential for sustainable semiconductor devices due to their low cost and inherent molecular self-assembly. Enhanced crystallinity and molecular orientation in thin films of solution-processable CPs have significantly improved organic electronic device performance. In this work, three methods, namely spin coating, dip coating, and unidirectional floating-film transfer method (UFTM), were utilized with their parametric optimization for fabricating RR-P3HT films. These films were then utilized for their characterization via optical and microstructural analysis to elucidate dominant roles of molecular orientation and crystallinity in controlling charge transport in organic field-effect transistors (OFETs). OFETs fabricated by RR-P3HT thin films using spin coating and dip coating displayed field-effect mobility (μ) of 8.0 × 10−4 cm2V−1s−1 and 1.3 × 10−3 cm2V−1s−1, respectively. This two-time enhancement in µ for dip-coated films was attributed to its enhanced crystallinity. Interestingly, UFTM film-based OFETs demonstrated μ of 7.0 × 10−2 cm2V−1s−1, >100 times increment as compared to its spin-coated counterpart. This superior device performance is attributed to the synergistic influence of higher crystallinity and molecular orientation. Since the crystallinity of dip-coated and UFTM-thin films are similar, ~50 times improved µ of UFTM thin films, this suggests a dominant role of molecular orientation as compared to crystallinity in controlling the charge transport.

DOI： 10.3390/mi15060677

DOI： 10.3390/mi15060677

Kyutacar

Proliferating optoelectronic properties of doped ZnO nanoparticles 査読有り 国際誌

Sharmila Chandran, Arthi Priscilla Ganesan, Nidhi Asthana, Shyam S. Pandey, Kshitij RB Singh, Arunadevi Natarajan

Journal of Molecular Structure ( Elsevier )   1311   138310(1) - 138310(8))   2024年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Ag-doped ZnO nanocomposites were synthesized precisely by adopting a wet chemical method to explore their optoelectronic characteristics for LED applications. Characterization studies have progressed for substantiation of its structural, and functional characteristics in conjugation with the optical properties of nanocomposites before and after doping. The metal-oxygen bonding was affirmed from IR spectra and excitation characteristics were detailed from UV–visible absorption spectra. The SEM images along with Energy dispersive X-ray analysis deliberates hexagonal morphology for pure ZnO which was surprisingly reformed into poly hexagon structures after doping with silver ions. The pertinence of the target material for LED application was verified by performing photoluminescence and charge density measurements. The doping of silver ions into ZnO presents a novel avenue in the field of optronics and serves as appropriate phosphors for light-emitting diodes. The application of the title compound was established by providing nano coating to LED bulb and emission efficiencies was recorded before and after coating. The present research recommends a unique method of nanocoating of LED bulb for efficient light intensity.

DOI： https://doi.org/10.1016/j.molstruc.2024.138310

DOI： https://doi.org/10.1016/j.molstruc.2024.138310

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S0022286024008305?via%3Dihub

Clarifying the Role of Carboxyl Functionality in Squaraine towards Aggregation and Self-assembly through Photophysical Characterization and BSA Interactions. 査読有り 国際誌

Sai Kiran Mavileti, Tamaki Kato, Shyam S. Pandey

Journal of Molecular Structure ( Elsevier )   1309   138226(1) - 138226(9)   2024年04月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The demand for near-infrared (NIR) probes with robust and stable fluorescence signals has surged, driven by their applications in optical sensing and bioimaging. Squraine dyes as NIR fluorescent probes have gained significant traction. However, understanding their behavior in aqueous media is important for their successful application. Herein we report the synthesis and photophysical characterization of carboxy-functionalized unsymmetrical squaraine dyes capable of light absorption and emission in the near-infrared (NIR) wavelength region. Structural variations in alkyl chain length, and spacer chain length between the primary chromophore and –COOH group were systematically introduced to investigate their impact on self-assembly in aqueous media leading to dye aggregation and their differential interactions with Bovine Serum Albumin (BSA) as a model protein. In phosphate buffer (PB) the absorption intensity decreased drastically along with pronounced shoulders due to dye aggregation leading to complete fluorescence quenching. However, in the presence of BSA, the intensity of shoulder bands reduced coupled with a sharp increase in the absorption associated with monomeric dye with the increasing concentration of BSA, indicating the prevention of dye aggregation owing to dye-BSA interactions. The prevention of dye aggregation due to dye-BSA interaction also led to a tremendous increase in the fluorescence intensities as a function of the increasing BSA concentrations. Site-selective study off BSA showed that these dyes bind preferably at Site-II using hydrophilic interactions. Thus, these dyes show great potential as FRET or fluorescent on/off probes for biosensing, non-covalent labeling of proteins, and fluorescent probes for bioimaging.

DOI： https://doi.org/10.1016/j.molstruc.2024.138226

DOI： https://doi.org/10.1016/j.molstruc.2024.138226

その他リンク： https://www.sciencedirect.com/science/article/pii/S0022286024007464?via%3Dihub

Targeted elimination of heavy metals from industrial wastewater: Synergistic effect of nano metal oxides 査読有り 国際誌

Manoharan Swathika, Narasimhan Muthulakshmi Andal, Sivasubramaniam Dharani, Jay Singh, Shyam S. Pandey, Kshitij RB Singh, Arunadevi Natarajan

Journal of the Taiwan Institute of Chemical Engineers ( Elsevier )   105485(1) - 105485(10)   2024年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Design and synthesis of pro-active nano metal oxides.

•
Advanced and cost-effective process for water treatment.

•
Comparative study probed the efficacies of target compound in heavy metal removal.

•
Upscaling the lab result to field samples to batch (96 %) and column method (98 %).

DOI： https://doi.org/10.1016/j.jtice.2024.105485

DOI： https://doi.org/10.1016/j.jtice.2024.105485

その他リンク： https://www.sciencedirect.com/science/article/pii/S1876107024001433?via%3Dihub

A Biocompatible NIR Squaraine Dye and Dye-Antibody Conjugates for Versatile Long-term In Vivo Fluorescence Bioimaging 査読有り 国際誌

Priyanka Balyan, Galyna Bila, Sai Kiran Mavileti, Evgenia Bila, Nazar Negrych, Shekhar Gupta, Linjun Tang, Rostyslav Bilyy, Shyam S. Pandey, Tamaki Kato

Materials Advances ( RSC )   5   3940 - 3949   2024年03月

　詳細を見る

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The demand for dependable near-infrared (NIR) probes, capable of sustained fluorescence within living systems and facile conjugation with biomolecules like antibodies and proteins, has been significantly on the rise, attributed to the substantial rise in the use of NIR imaging techniques and devices, with extensive integration into clinical diagnostics. Antibody conjugates are vital for targeted and selective bioimaging, enabling precise visualization of specific biomolecules within complex biological systems. Their multiplexing capability allows simultaneous detection of multiple targets, while their dynamic imaging capability enables real-time monitoring of cellular processes. Clinically, antibody conjugates have significant applications in disease prognosis, diagnosis, and monitoring. In this work, we report the synthesis of a new symmetrical NIR squaraine dye (SQ-58) with multiple carboxy anchoring groups for ease of coupling with antibodies. The dye showed decreased absorption and fluorescence intensity in phosphate buffer (PB) due to enhanced dye-aggregate formation. However, in the presence of bovine serum albumin (BSA) in PB, SQ-58 showed an enhanced fluorescence signal along concentrations of BSA. SQ-58 showed no cytotoxicity when tested in white laboratory mice while providing strong fluorescence when injected in vivo. Conjugation of SQ-58 through the carboxylic groups to the isotypic mouse IgG antibodies (IgG-SQ-58) resulted in uniform distribution of the targeted molecule in the whole cardiovascular system. The NIR signal of IgG-SQ-58 was stable for at least 7 days allowing the possibility of long-term imaging. Conjugation of SQ-58 to antibodies raised against NK-Ly lymphoma tumor cells allowed efficient discrimination of tumor cells grown in the abdomen of laboratory mice. Thus, to the best of our knowledge, we report for the first time a biocompatible NIR dye, SQ-58, that can be easily conjugatable to biomolecules, and its antibody conjugates for a wide range of bioimaging applications.

DOI： https://doi.org/10.1039/d4ma00212a

DOI： https://doi.org/10.1039/d4ma00212a

その他リンク： https://pubs.rsc.org/en/content/articlelanding/2024/ma/d4ma00212a

Design and Synthesis of Novel Squaraine-Based Fluorescent Probe for Far-Red Detection of Chymotrypsin Enzyme 査読有り 国際誌

Shekhar Gupta, Priyanka, Sai Kiran Mavileti, Shyam S. Pandey, Tamaki Kato

Molecules ( MDPI )   29 ( 6 )   1282(1) - 1282(14)   2024年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Chymotrypsin, a crucial enzyme in human digestion, catalyzes the breakdown of milk proteins, underscoring its significance in both health diagnostics and dairy quality assurance. Addressing the critical need for rapid, cost-effective detection methods, we introduce a groundbreaking approach utilizing far-red technology and HOMO-Förster resonance energy transfer (FRET). Our novel probe, SQ-122 PC, features a unique molecular design that includes a squaraine dye (SQ), a peptide linker, and SQ moieties synthesized through solid-phase peptide synthesis. Demonstrating a remarkable quenching efficiency of 93.75% in a tailored H2O:DMSO (7:3) solvent system, our probe exhibits absorption and emission properties within the far-red spectrum, with an unprecedented detection limit of 0.130 nM. Importantly, our method offers unparalleled selectivity towards chymotrypsin, ensuring robust and accurate enzyme detection. This pioneering work underscores the immense potential of far-red-based homo-FRET systems in enabling the sensitive and specific detection of chymotrypsin enzyme activity. By bridging the gap between cutting-edge technology and biomedical diagnostics, our findings herald a new era of enzyme sensing, promising transformative advancements in disease diagnosis and dairy quality control.

DOI： https://doi.org/10.3390/molecules29061282

DOI： https://doi.org/10.3390/molecules29061282

その他リンク： https://www.mdpi.com/1420-3049/29/6/1282

The Influence of a Microstructural Conformation of Oriented Floating Films of Semiconducting Polymers on Organic Device Performance 査読有り 国際誌

Shubham Sharma, Kumar Vivek Gaurav, Shuichi Nagamatsu, Shyam S. Pandey

Polymers ( MDPI )   16 ( 5 )   710(1) - 710(13)   2024年03月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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Open AccessArticle
The Influence of a Microstructural Conformation of Oriented Floating Films of Semiconducting Polymers on Organic Device Performance
by Shubham Sharma 1,*ORCID,Kumar Vivek Gaurav 1ORCID,Shuichi Nagamatsu 2 andShyam S. Pandey 1,*ORCID
1
Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu 808-0196, Japan
2
Department of Computer Science and Electronics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka 820-8502, Japan
*
Authors to whom correspondence should be addressed.
Polymers 2024, 16(5), 710; https://doi.org/10.3390/polym16050710
Submission received: 24 January 2024 / Revised: 27 February 2024 / Accepted: 4 March 2024 / Published: 5 March 2024
(This article belongs to the Special Issue New Progress in Semiconducting Polymer Nanoparticles)
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Abstract
Extended π-conjugation with backbone-planarity-driven π-π stacking dominates charge transport in semiconducting polymers (SCPs). The roles of SCP film morphology and macromolecular conformation concerning the substrate in influencing charge transport and its impact on device performance have been a subject of extensive debate. Face-on SCPs promote out-of-plane charge transport primarily through π-π stacking, with conjugated polymeric chains assisting transport in connecting crystalline domains, whereas edge-on SCPs promote in-plane charge transport primarily through conjugation and π-π stacking. In this work, we fabricated three different types of devices, namely, organic field effect transistors, organic Schottky diodes, and organic bistable memristors, as representatives of planar and vertical devices. We demonstrate that a planar device, i.e., an organic field effect transistor, performs well in an edge-on conformation exhibiting a field-effect mobility of 0.12 cm2V−1s−1 and on/off ratio >104, whereas vertical devices, i.e., organic Schottky diodes and organic memristors, perform well in a face-on conformation, exhibiting exceptionally high on/off ratios of ~107 and 106, respectively.

DOI： https://doi.org/10.3390/polym16050710

DOI： https://doi.org/10.3390/polym16050710

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その他リンク： https://www.mdpi.com/2073-4360/16/5/710

Aloe Vera Gel (Aloe barbadensis Miller) Derived Self-Assembled Flower-Shaped Carbon Quantum Dots Interface for Ultra-Sensitive Electrochemical Detection of the Endocrine Disruptor Bisphenol-A 査読有り 国際誌

Ankur Srivastava, Kshitij R, B. Singh, Khrsheed Khrsheed Ahmed, Ravindra Pratap Singh, Mrituanjay D. Pandey, Shyam S. Pandey, Jay Singh

New Journal of Chemistry ( RSC )   48   5543 - 5552   2024年02月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

This manuscript is focused on the synthesis of biologically derived carbon quantum dots (CQDs) via hydrothermal methods using Aloevera leaves (Aloe barbadensis miller). The proposed biochemical route, utilizing Aloevera gel, has garnered attention due to its cost-effectiveness, eco-friendly nature, and ability to produce highly pure, stable, and fluorescent biologically derived self-assembled nanoparticles measuring approximately 5–6 nm in size. The primary objective was to harness plant sources and establish a sustainable and renewable platform for synthesizing valuable nanostructures, encouraging researchers to shift their focus from unhealthy chemicals to natural resources for healthier and non-polluting investigations. The synthesized CQDs exhibited remarkable colloidal properties, excellent fluorescence, and photostability under UV light. Characterization techniques such as powder XRD, UV-Vis spectroscopy, photoluminescence, FT-IR, AFM, and TEM were employed to analyse the prepared CQDs. Furthermore, the prepared CQDs displayed significant electrochemical behaviour in the presence of tyrosinase enzyme to detect Bisphenol-A, which functions as an endocrine disruptor (ED). These nanomaterials were also utilized for electrochemical biosensing applications. Additionally, the fabricated CQDs exhibited unique structural and morphological characteristics, along with efficient electrochemical properties, which are thoroughly discussed in the manuscript.

DOI： https://doi.org/10.1039/D4NJ00061G

DOI： https://doi.org/10.1039/D4NJ00061G

その他リンク： https://pubs.rsc.org/en/content/articlelanding/2024/nj/d4nj00061g

Hetero atom-based metal complexes as emitters in organic light-emitting diodes 査読有り 国際誌

https://www.sciencedirect.com/science/article/pii/S002228602400187X?via%3Dihub

Journal of Molecular Structure ( Elsevier )   1304   137664(1) - 137664(13)   2024年01月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The new, more energy-efficient lighting systems and high-quality displays for new age digital devices is the demand of the current generation. In this regard, focused and deliberated research has been done on transition metal complexes as effective building blocks for organic light-emitting diodes (OLEDs). The activity of divalent metallic compounds was investigated through spotlighting Co (II), Ni (II), and Cu (II) metal ions with guanidinium naphthoate as blue phosphors in OLEDs. Using spectroscopic and diffraction techniques, the phosphors produced at the optimal temperature were studied both structurally and thermally. Additionally, the target compound's photophysical investigations in a variety of organic solvents with differing polarities were examined, and the findings were presented. Because of their quick photoluminescence response time and high emission quantum efficiency, Ni (II) complexes have drawn specific attention. Ni (II) complexes precisely exhibit thermally activated delayed fluorescence (TADF) and found to be the most promising materials for future lighting technology. We compared the efficiencies of various complexes in this study to provide an overview of the development of OLEDs. To affirm the pertinency of the synthesized compounds as phosphors, studies like photoluminescence, correlated color temperature, color purity, Duv, and the Television Lighting Consistency Index (TLCI) were performed and their photometric properties were also deliberated. Ni (II) shows an magnificent luminescence character and maximum coloring index for light sources and found to be an essential component for OLEDs.

DOI： https://doi.org/10.1016/j.molstruc.2024.137664

DOI： https://doi.org/10.1016/j.molstruc.2024.137664

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Controlling adsorption of two dyes on TiO2 surface to improve the efficiency of see-through dye-sensitized solar cells 査読有り 国際誌

https://www.sciencedirect.com/science/article/pii/S0038092X24000331

Solar Energy ( Elsevier )   269   112339(1) - 112339(11)   2024年01月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Transparent dye-sensitized solar cells (DSSCs) were fabricated utilizing judiciously selected blue-absorbing (D-131) and red-absorbing (SQ-140) two sensitizing dyes. These dyes exhibit complementary light absorption along with the least optical absorption in the 500 nm-600 nm wavelength region. This is helpful to impart not only high average visible transparency (AVT) but also high photoconversion efficiency (PCE). D-131 exhibits not only an approximately 1.5 times higher adsorption speed but also an approximately 4 times stronger binding on the TiO2. Stepwise dye adsorption on TiO2 was conducted to suppress unwanted and non-favourable inter-dye interactions. It has been demonstrated that when the SQ-140 adsorbed substrate was subjected to further dye adsorption by the D-131, there was a replacement of the SQ-140 by the D-131 reaching the optimal presence of both of the dyes in 20–30 min giving the best PCE of 4.5 %. However, in the opposite sequence of dye adsorption, there was no replacement of D-131 by SQ-140, rather SQ-140 was adsorbed in the available surface on the mesoporous TiO2 adsorbed with D-131. In this 2nd case, the optimal presence of both dyes is attained in 40 min of adsorption by SQ-140 giving the best PCE of 5.45 %. Transparent DSSCs fabricated using stepwise co-sensitized photoanodes demonstrated an AVT of 47.5 % and 26.5 % with thinner (single-layer) and thicker (double-layer) mesoporous TiO2, respectively.

DOI： https://doi.org/10.1016/j.solener.2024.112339

DOI： https://doi.org/10.1016/j.solener.2024.112339

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Fabrication of All-Polymer Organic Phototransistors Utilizing Oriented P3HT 査読有り

Tejswini K. Lahane, Shubham Sharma, Harshita Rai, Moulika Desu, Yoshito Ando, Shyam S. Pandey, and Vipul Singh

IEEE Sensor Letters ( IEEE )   8 ( 2 )   3500304(1) - 3500304(4))   2023年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

High flexibility and solution processability have made all polymer organic pho-totransistors (AP-OPTs) a suitable candidate for various wearable and smart home applications. However, fabrication of the AP-OPTs via the solution process is still challenging owing to the possible degradation of the polymer gate dielectric layer by the solvent of the organic semiconductor, resulting in hampered device performance. To circumvent this issue, the unidirectional floating film transfer method, having the least impact on the underlying organic dielectric film, has been used to obtain highly oriented poly (3-hexylthiophene) (P3HT) thin film. Further, the effect of P3HT film orientation with respect to the channel has been investigated. Results revealed that the device with parallel orientation performed better with photosensitivity of 5 × 10 3 and photoresponsivity of 133 A/W.

DOI： 10.1109/LSENS.2023.3347760

DOI： 10.1109/LSENS.2023.3347760

Kyutacar

その他リンク： https://ieeexplore.ieee.org/document/10376029

Enhancement in Capacitance of Ionic Type of EAP-Based Strain Sensors 査読有り 国際誌

Nitin KUMAR Singh, Kazuto Takashima, Shyam S Pandey

Sensors ( MDPI )   23 ( 23 )   9400(1) - 9400(19)   2023年11月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

This paper aims to enhance the capacitance of electroactive polymer (EAP)-based strain sensors. The enhancement in capacitance was achieved by using a free-standing stretchable polymer film while introducing conducting polymer to fabricate a hybrid dielectric film with controlled conductivity. In this work, styrene-ethylene-butylene-styrene (SEBS) rubber was used as the base material, and dodecyl benzene sulfonate anion (DBSA)-doped polyaniline (PANI) was used as filler to fabricate a hybrid composite conducting film. The maleic anhydride group of the SEBS Rubber and DBSA, the anion of the polyaniline dopant, make a very stable dispersion in Toluene and form a free-standing stretchable film by solution casting. DBSA-doped polyaniline increased the conductivity and dielectric constant of the dielectric film, resulting in a significant enhancement in the capacitance of the EAP-based strain sensor. The sensor presented in this article exhibits capacitance values ranging from 24.7 to 100 µF for strain levels ranging from 0 to 100%, and sensitivity was measured 3 at 100% strain level.

DOI： https://doi.org/10.3390/s23239400

DOI： https://doi.org/10.3390/s23239400

その他リンク： https://www.mdpi.com/1424-8220/23/23/9400

Squaric Acid Core Substituted Unsymmetrical Squaraine Dyes for Dye-Sensitized Solar Cells: Effect of Electron Acceptors on Their Photovoltaic Performance 査読有り 国際誌

Safalmani Pradhan, Yuki Kurokawa, Suraya Shaban, Shyam S Pandey

Colorants ( MDPI )   2 ( 4 )   654 - 673   2023年11月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The design and development of sensitizing dyes possessing wide-wavelength photon harvesting encompassing visible to near-infrared (NIR) wavelength regions are unavoidable for increasing the overall efficiency of dye-sensitized solar cells (DSSCs). In this study, three far-red-sensitive squaraine sensitizers were designed computationally, synthesized, and characterized, aiming towards their suitability as a potential sensitizer for DSSCs. It has been found that the incorporation of an electron acceptor moiety in the central squaraine core brought about a red shift in the absorption maximum (λmax) and the emergence of a secondary absorption band in the blue region, thus broadening the photon-harvesting window. In addition, it also lowered the dye’s HOMO energy level enabling a facile regeneration of the photo-excited dye, which improved the photovoltaic performance of SQ-223, exhibiting a photoconversion efficiency (PCE) of 4.67%. Thereafter, to address the issue of wide-wavelength photon harvesting, DSSCs were fabricated by co-adsorbing two complementary dyes SQ-223 and D-131 in various molar ratios. The DSSC fabricated with D-131 and SQ-223 in 9:1 molar ratio displayed the best photovoltaic performance with a PCE of 5.81%, a significantly higher PCE when compared to corresponding individual dye-based DSSCs containing D-131 (3.94%) and SQ-223 (4.67%).

DOI： https://doi.org/10.3390/colorants2040034

DOI： https://doi.org/10.3390/colorants2040034

Kyutacar

その他リンク： https://www.mdpi.com/2079-6447/2/4/34

Deposition of Transparent Ag Nanowires‐Based Top Electrode for the Development of Double‐Side Green Light Hybrid Photodetector 査読有り 国際誌

Tejswini K. Lahane, Jitesh Agrawal, Yoshito Ando, Shyam S. Pandey, Vipul Singh

Physica Status Solidi-A ( Wiley )   220 ( 24 )   2300166 (1) - 2300166 (8)   2023年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Herein, various silver nanowires (AgNWs) deposition techniques, i.e., spin coating, Mayer rod coating, and spray coating are used to fabricate ZnO/P3HT-based double-side hybrid photodetectors and their photoresponse for 520 nm green light has been compared. The electrodes are coated over the polyethylene terephthalate sheet separately and laminated over the indium tin oxide (ITO)/ZnO/P3HT. Mayer rod-coated electrodes are found to have a sheet resistance (Rsh) of 24 Ω Sq.−1 and a light transmission of 91%. Additionally, spin- and spray-coated AgNW electrodes exhibit Rsh of 20 and 23 Ω Sq.−1, respectively, along with 80% and 85% transparencies. As the device consists of transparent electrodes on both sides, it can detect light from both the top and bottom sides. Mayer rod-coated AgNW electrode-based device has produced better photosensitivity of 1500 (for ITO side illumination) and 630 (for AgNWs side illumination) at λ = 525 nm. Further, the device has demonstrated the responsivity of 124 mAW−1 and specific detectivity of 3 × 1011 Jones.

DOI： https://doi.org/10.1002/pssa.202300166

DOI： https://doi.org/10.1002/pssa.202300166

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その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300166

Bioinspired Multifunctional Silver Nanoparticles for Optical Sensing Applications: A Sustainable Approach 招待有り 査読有り 国際誌

Kshitij RB Singh, Arunadevi Natarajan, Shyam S. Pandey

https://doi.org/10.1021/acsabm.3c00669 ( American Chemical Society )   6 ( 11 )   4549 - 4571   2023年10月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Silver nanoparticles developed via biosynthesis are the most fascinating nanosized particles and encompassed with excellent physicochemical properties. The bioinspired nanoparticles with different shapes and sizes have attracted huge attention due to their stability, low cost, environmental friendliness, and use of less hazardous chemicals. This is an ideal method for synthesizing a range of nanosized metal particles from plants and biomolecules. Optical biosensors are progressively being fabricated for the attainment of sustainability by using opportunities offered by nanotechnology. This review focuses mainly on tuning the optical properties of the metal nanoparticles for optical sensing to explore the importance and applications of bioinspired silver nanoparticles. Further, this review deliberates the role of bioinspired silver nanoparticles (Ag NPs) in biomedical, agricultural, environmental, and energy applications. Profound insight into the antimicrobial properties of these nanoparticles is also appreciated. Tailor-made bioinspired nanoparticles with effectuating characteristics can unsurprisingly target tumor cells and distribute enwrapped payloads intensively. Existing challenges and prospects of bioinspired Ag NPs are also summarized. This review is expected to deliver perceptions about the progress of the next generation of bioinspired Ag NPs and their outstanding performances in various fields by promoting sustainable practices for fabricating optical sensing devices.

DOI： https://doi.org/10.1021/acsabm.3c00669

DOI： https://doi.org/10.1021/acsabm.3c00669

その他リンク： https://pubs.acs.org/doi/10.1021/acsabm.3c00669

Regulation of neuroinflammation in Alzheimer's disease via nanoparticle-loaded phytocompounds with anti-inflammatory and autophagy-inducing properties 査読有り 国際誌

Vinayak Nayak Sushmita Patra Shrushti Rou Atala Bihari Jena Rohit Sharma Kali Prasad Pattanaik Jay Singh Shyam S. Pandey Ravindra Pratap Singh Sanatan Majhi Kshitij RB Singh Rout George Kerry

Phytomedicine ( Elsevier )   122   155150 (1) - 155150 (22)   2023年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Alzheimer's disease (AD) is characterized by neuroinflammation linked to amyloid β (Aβ) aggregation and phosphorylated tau (τ) protein in neurofibrillary tangles (NFTs). Key elements in Aβ production and NFT assembly, like γ-secretase and p38 mitogen-activated protein kinase (p38MAPK), contribute to neuroinflammation. In addition, impaired proteosomal and autophagic pathways increase Aβ and τ aggregation, leading to neuronal damage. Conventional neuroinflammation drugs have limitations due to unidirectional therapeutic approaches and challenges in crossing the Blood-Brain Barrier (BBB). Clinical trials for non-steroidal anti-inflammatory drugs (NSAIDs) and other therapeutics remain uncertain. Novel strategies addressing the complex pathogenesis and BBB translocation are needed to effectively tackle AD-related neuroinflammation.

DOI： https://doi.org/10.1016/j.phymed.2023.155150

DOI： https://doi.org/10.1016/j.phymed.2023.155150

その他リンク： https://www.sciencedirect.com/science/article/pii/S0944711323005093?via%3Dihub

Chitosan stabilized copper iodide nanoparticles enabled nano-bio-engineered platform for efficient electrochemical biosensing of dopamine 査読有り 国際誌

Kshitij RB Singh, Pooja Singh, Sadhucharan Mallick, Jay Singh, Shyam S. Pandey

International Journal of Biological Macromolecules ( Elsevier )   253 ( 8 )   127587(1) - 127587(12)   2023年09月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Neurodegenerative disorders are one of the significant challenges to the aging society, as per the United Nations, where 1 in 6 people globally over 65 years of age are expected to suffer by 2050. The exact pathophysiological root of these disorders is although not known adequately, but reduced dopamine (most significant neurotransmitters) levels have been reported in people affected by Parkinson's disease. Sensitive detection and effective monitoring of dopamine can help to diagnose these neurodegenerative disorders at a very early stage, which will help to properly treat these disorders and slow down their progression. Therefore, it is crucial to detect physiological and clinically acceptable amounts of dopamine with high sensitivity and selectivity in basic pathophysiology research, medication, and illness diagnosis. Here in this present investigation, nano-bio-engineered stable chitosan stabilized copper iodide nanoparticles (CS@CuI NPs) were synthesized to engineer the active biosensing platform for developing dopamine biosensors. Initially, the as-synthesized nano-bio-engineered CS@CuI NPs were subjected to its drop-casting onto an Indium tin oxide (ITO) conducting glass substrate. This substrate platform was then utilized to immobilize tyrosinase (Tyr) enzyme by drop-casting to fabricate Tyr/CS@CuI NPs/ITO bioelectrode for the ultrasensitive determination of dopamine. Several techniques were used to characterize the structural, optical, and morphological properties of the synthesized CS@CuI NPs and Tyr/CS@CuI NPs/ITO bioelectrode. Further, the as-prepared bioelectrode was evaluated for its suitability and electrocatalytic behaviour towards dopamine by cyclic voltammetry. A perusal of the electroanalytic results of the fabricated biosensor revealed that under the optimized experimental conditions, Tyr/CS@CuI NPs/ITO bioelectrode exhibits a very high electrochemical sensitivity of 11.64 μA μM−1 cm−2 towards dopamine with the low limit of detection and quantification of 0.02 and 0.386 μM, respectively. In addition, the fabricated bioelectrode was stable up to 46 days with only 4.82 % current loss, reusable till 20 scans, and it also performed effectively while real sample analysis. Therefore, the nano-bio-engineered biosensor platform being reported can determine deficient dopamine levels in a very selective and sensitive manner, which can help adequately manage neurodegenerative disorders, further slowing down the disease progression.

DOI： https://doi.org/10.1016/j.ijbiomac.2023.127587

DOI： https://doi.org/10.1016/j.ijbiomac.2023.127587

その他リンク： https://www.sciencedirect.com/science/article/pii/S0141813023044859?via%3Dihub

Symbiotic study of N-bridged metal complexes as electrocatalysts for hydrogen evolution reaction 査読有り 国際誌

Arunadevi Natarajan, M. Swathika, Kshitij RB Singh, Ranjana Verma, Shyam S. Pandey, Jay Singh

International Journal of Hydrogen Energy ( Elsevier )   52 ( A )   1458 - 1471   2023年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Design and fabrication of non-noble metal catalysts for the extensive generation of H2 (hydrogen) gas by water splitting is the upsurging field aiming towards the sustainable environment and need the future clean and green energy. However, scheming and understanding the basic principle regulating the activity of the catalyst is still inexplicable. Although Pt is currently the material of choice owing to its high electrocatalytic activities but need for its high loading and high cost is an intriguing issue needing amicable solution. The hybrid structures of heteroatom-based transition metal complexes are more effective and are cost effective electrocatalysts for hydrogen production. In this proposed work, the electrocatalytic behaviour of alkali (Li+, Na+, K+) and alkaline metal (Ca2+, Sr2+, Ba2+) was figured out along with their synthetic procedure and characterization. Owing to their high complexing ability, ring formation, and bidentate nature, substituted naphthoic acid and aminoguanidine were chosen as bridging ligands. The thermodynamic stability and best catalytic behaviour of synthesized alkali and alkaline earth metals were compared and presented based on electrochemical studies. Linear sweep voltammetry (LSV) curves display excellent activity and Tafel slope was found in the range of 6.38–40 mVdec−1 in 0.5 M H2SO4. The electrochemical impedance spectroscopy (EIS) test was accomplished to recognize the mechanism of HER, and charge transfer resistance was less which indicates that composites are favourable for the hydrogen evolution. The electrochemical surface area (ECSA) was figured by studying the electric double layer capacitance (C dl) and it was found to be 0.377 μFcm2 - 0.143 μFcm2. More prominent ECSA values implies, the target complexes have enhanced electrochemically active/dynamic sites and better hydrogen evolution performance. According to the results, high-performing catalytically active sites are found to be Li [1NA-AMG] metal ions, thus showing a potential method for electrocatalyst engineering. Furthermore, in a volcano plot, the position of the Li [1NA-AMG] metal ions is found to be close to the apex with near thermoneutral catalytic activity. Based on the results, we successfully designed an electrocatalyst as a prospective candidate for hydrogen evolution reaction.

DOI： https://doi.org/10.1016/j.ijhydene.2023.07.305

DOI： https://doi.org/10.1016/j.ijhydene.2023.07.305

その他リンク： https://www.sciencedirect.com/science/article/pii/S0360319923038582?via%3Dihub

Fabrication and Characterization of Bifacial Dye-Sensitized Solar Cells Utilizing Indoline Dye with Iodine and Cobalt-based Redox Electrolytes 査読有り 国際誌

Suraya Shaban, Safalmani Pradhan, Shyam S. Pandey

Physica Status Solidi-A ( Elsevier )   220 ( 24 )   2300241 (1) - 2300241 (7)   2023年08月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Bifacial solar cells are gaining popularity due to their compactness, space-saving property, and higher photoconversion efficiency (PCE) than mono-facial solar cells. Bifacial dye-sensitized solar cells (BF-DSSCs) are fabricated and characterized utilizing D-205 as a dye sensitizer in combination with I−/I3− and Co2+/Co3+ redox electrolytes. BF-DSSCs using iodine-based electrolytes demonstrate a cumulative PCE and bifaciality factor (BFF) of 13.05% and 85%, respectively. The hampered PCE under backside light illumination is attributed to the absorption of photons by the electrolyte itself. Contrary to this, BF-DSSCs fabricated using cobalt-complex-based redox electrolyte exhibits an exceptionally high BFF of nearly 100% with a PCE of 4.77% and 4.75% under the front- and rear-light illumination, respectively. Although the open-circuit voltage of the BF-DSSCs fabricated using cobalt electrolyte (with deeper redox potential) is slightly higher than that of BF-DSSCs fabricated using iodine electrolyte, their cumulative PCE (9.52%) is much lower than that of iodine-based device counterparts (13.05%). This decrease in PCE is attributed to the relatively fast charge recombination in the cobalt-electrolyte-based BF-DSSCs.

DOI： https://doi.org/10.1002/pssa.202300241

DOI： https://doi.org/10.1002/pssa.202300241

Kyutacar

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300241

The role of solvents in the microstructure and charge transport of semiconducting polymer films prepared at the air–liquid interface 査読有り 国際誌

Manish Pandey, Jumpei Toyoda, Shubham Sharma, Yongyoon Cho, Hiroaki Benten, Shyam S Pandey, Masakazu Nakamura

Journal of Materials Chemistry C ( RSC )   11   12364 - 12373   2023年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Charge transport in semiconducting polymers (SCPs) is strongly influenced by their film microstructure. Fabrication of SCP floating films at the air–liquid interface offers numerous advantages over conventional solution processing. The casting solvent plays a crucial role in forming film microstructures, which has been extensively studied for various fabrication methods. However, floating films of SCPs are generally processed with a single solvent, and the role of their boiling point (Tb) or solubility of individual solvents (or blends) has never been considered. In this report, we have systematically studied the effect of different solvents and blends on the film microstructure and field-effect transistor (FET) mobility of three well-known SCPs, PQT, PBTTT and P(NDI2OD-T2). We used the unidirectional floating film transfer method (UFTM) and interfacial spreading to fabricate large-area oriented and isotropic films, respectively. The detailed analysis of the film microstructure, macroscopic orientation and FET mobility of the films of these SCPs processed with different solvents has been studied. Our results clarify that a low Tb solvent (<90 °C) is a prerequisite for obtaining uniform large-area oriented films, and films processed with high Tb solvents are isotropic. As expected, the effect of Tb of the solvent on the orientation of SCPs and FET mobility is different for various SCPs under consideration. Instead, the variation of FET mobility is linked to the optical dichroic ratio (polymer orientation), interchain ordering in films and the presence of fiber-like aggregates.

DOI： https://doi.org/10.1039/D3TC02282J

DOI： https://doi.org/10.1039/D3TC02282J

その他リンク： https://pubs.rsc.org/en/content/articlelanding/2023/tc/d3tc02282j/unauth

Design, Synthesis and Photophysical Characterization of Multifunctional Far-red Squaraine Dyes for Dye-Sensitized Solar Cells 査読有り 国際誌

Kota Mori, Yuki Kurokawa, Sai Kiran Mavileti, Shyam S Pandey

Physica Status Solidi-A ( Wiley )   220 ( 24 )   2023年08月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Novel far-red sensitive symmetrical squaraine (SQ) dyes aiming toward multifunctional properties such as control of dye aggregation, promotion of molecular self-assembly, and introduction of electrolyte function by alkyl chain terminal modification are designed. Newly designed dyes without terminal modification as reference (SQ-5) along with iodine (SQ-77) and imidazole (SQ-79) alkyl terminal-modified dyes are successfully synthesized, characterized, and subjected to detailed photophysical investigations. Iodine terminal modification (SQ-77) leads to enhanced molar extinction coefficient, dye aggregation, dye loading, and binding strength on the TiO2 surface, which is found by just the opposite after the imidazole (SQ-79) terminal modification. Demonstration of nearly similar photovoltaic performance by SQ-77 and SQ-79 in the absence of iodine and chenodeoxycholic acid validates their multifunctional role as electrolyte function and dye aggregation prevention, respectively, in addition to their main role as photosensitizer. Dye-sensitized solar cells fabricated with SQ-5 as a sensitizer show efficient far-red to near-infrared photo sensitization and photon harvesting with short-circuit photocurrent density, open-circuit voltage, and fill factor of 11.98 mA cm−2, 0.61 V, and 0.57, respectively, leading to a photoconversion efficiency of 4.2% under simulated solar irradiation.

DOI： https://doi.org/10.1002/pssa.202300254

DOI： https://doi.org/10.1002/pssa.202300254

Kyutacar

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300254

Enhancing the Performance of Organic Phototransistors Based on Oriented Floating Films of P3HT Assisted by Al-Island Deposition 査読有り 国際誌

Tejswini K. Lahane, Shubham Sharma, Moulika Desu, Yoshito Ando, Shyam S. Pandey, Vipul Singh

Materials ( MDPI )   16   5249(1) - 5249(12)   2023年07月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The fabrication of high-performance Organic Phototransistors (OPTs) by depositing Al-islands atop Poly(3-hexylthiophene) (P3HT) thin film coated using the unidirectional floating-film transfer method (UFTM) has been realized. Further, the effect of Al-island thickness on the OPTs’ performance has been intensively investigated using X-ray photoelectron spectroscopy, X-ray Diffraction, Atomic force microscopy and UV-Vis spectroscopy analysis. Under the optimized conditions, OPTs’ mobility and on–off ratio were found to be 2 × 10−2 cm2 V−1 s−1 and 3 × 104, respectively. Further, the device exhibited high photosensitivity of 105, responsivity of 339 A/W, detectivity of 3 × 1014 Jones, and external quantum efficiency of 7.8 × 103% when illuminated with a 525 nm LED laser (0.3 mW/cm2).

DOI： https://doi.org/10.3390/ma16155249

DOI： https://doi.org/10.3390/ma16155249

Kyutacar

その他リンク： https://www.mdpi.com/1996-1944/16/15/5249

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics 査読有り 国際誌

Vinayak Nayak, Sushmita Patra, Kshitij RB Singh, Bristy Ganguly, Das Nishant Kumar, Deepak Panda, Ganesh Kumar Maurya, Jay Singh, Sanatan Majhi, Rohit Sharma, Shyam S. Pandey, Ravindra Pratap Singh, Rout George Kerry

Environmental Research ( Elsevier )   235   116573(1) - 116573(31)   2023年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

DOI： https://doi.org/10.1016/j.envres.2023.116573

DOI： https://doi.org/10.1016/j.envres.2023.116573

その他リンク： https://www.sciencedirect.com/science/article/pii/S0013935123013774?via%3Dihub

Facile Fabrication and Characterization of Oriented and Multilayer Thin Films of Solution Processable Conjugated Polymer 査読有り 国際誌

Shubham Sharma, Shuichi Nagamatsu, Vipul Singh, Shyam S. Pandey

Physica Status Solidi-A ( Elsevier )   220 ( 24 )   2300194 (1) - 2300194 (7)   2023年07月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Fabrication of multilayer thin films of solution-processable organic semiconductors has great potential in organic electronics, but adopting existing thin-film techniques to attain this is highly cumbersome. Herein, a unique unidirectional floating film transfer method has been utilized, which allows the facile fabrication of large area and oriented thin films of conjugated polymers. This method has successfully fabricated and characterized multilayer and oriented thin films of regioregular poly(3-hexylthiophene) without having any adverse effect on the underlying layers. Optical characterizations reveal that fabricated thin films are anisotropic with a dichroic ratio of 2.2 having a single layer thickness of 14.5 nm. X-ray diffraction results demonstrate uniformity in the crystallinity of the multilayered thin film with comparable crystallite size and interplanar spacing with purely edge-on molecular orientation. The organic field effect transistor fabricates using multilayer thin films and also exhibits a uniform and saturated charge carrier mobility of about 0.1 cm2  V−1 s−1.

DOI： https://doi.org/10.1002/pssa.202300194

DOI： https://doi.org/10.1002/pssa.202300194

Kyutacar

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300194

Gold nanoparticle assisted colorimetric biosensors for rapid polyethylene terephthalate (PET) sensing for sustainable environment to monitor microplastics 査読有り 国際誌

Abhishek Behera, Soumya Ranjan Mahapatra, Sanatan Majhi, Namrata Misra, Rohit Sharma, Jay Singh, Ravindra Pratap Singh, Shyam S. Pandey, Kshitij RB Singh, Rout George Kerry

Environmental Research ( Elsevier )   234   116556(1) - 116556(10)   2023年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

The extremely widespread and ubiquitous nature of plastics, estimated to boost its global production by 26 billion tons till 2050. The large chunks of plastic waste that decomposed down to micro- or nano plastics (MNPs) leads to various ill effects on biological entities. The conventional PET detection methods lack rapid detection of microplastics due to variances in microplastic features, long-drawn-out sample pre-processing procedures and complex instrumentation. Therefore, an instantaneous colorimetric evaluation of microplastic will ensures the simplicity of conducting assays on field. Several nanoparticle-based biosensors that detects proteins, nucleic acids, metabolites operate on either cluster or disperse state of nanoparticle. However, gold nanoparticle (AuNPs) emerges an ideal scaffold for sensory element in lateral flow biosensors due to their simple surface functionalization, unique optoelectronic properties and varied colour spectrum depending on morphologies and aggregation state. In this paper an effort has been made in the form of a hypothesis using in silico tools as a basis to detect polyethylene terephthalate (PET) – most abundant type of microplastic using gold nanoparticle based lateral flow biosensor. We retrieved sequences of PET-binding synthetic peptides and modelled their 3-D structure using I-Tasser server. The best protein model for each peptide sequences are docked with PET monomers – BHET, MHET and other PET polymeric ligands, to evaluate their binding affinities. The synthetic peptide SP 1 (WPAWKTHPILRM) docked with BHET and (MHET)4 exhibits 1.5-fold increases in binding affinity as compared to reference PET anchor peptide Dermaseptin SI (DSI). The GROMACS molecular dynamics simulation studies of synthetic peptide SP 1 - BHET & - (MHET)4 complexes for 50 ns further confirmed the stable binding. RMSF, RMSD, hydrogen bonds, Rg and SASA analysis provides useful structural insights of the SP 1 complexes as compared to reference DSI. Furthermore, SP 1 functionalized AuNP-based colorimetric device was described in detail for detection of PET.

DOI： https://doi.org/10.1016/j.envres.2023.116556

DOI： https://doi.org/10.1016/j.envres.2023.116556

その他リンク： https://www.sciencedirect.com/science/article/pii/S0013935123013609?via%3Dihub

Controlling the TiO 2 –Dye Nanomolecular Interactions for Improving the Photoconversion in Transparent Dye‐Sensitized Solar Cells 査読有り 国際誌

Pritha Roy, Yuki Kurokawa, Shyam S. Pandey

Physica Status Solidi-A ( Wiley )   220 ( 4 )   2300158 (1) - 2300158 (8)   2023年06月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Herein, transparent dye-sensitized solar cells (DSSCs) are fabricated using two sensitizing dyes aiming toward panchromatic photon harvesting following two different approaches of dye adsorption such as using dye cocktail and sequential dye adsorption. A combination of complementary yellow-colored dye (D-131) and green-colored far-red-sensitive squaraine dye (SQ-140) is judiciously selected not only for panchromatic light absorption but also for bypassing the absorption in the high eye-sensitivity wavelength region (500–600 nm) region to improve the transparency. The DSSC fabricated using a dye cocktail of D-131 and SQ-140 in a 9:1 molar ratio exhibits a photoconversion efficiency (PCE) and average visible transparency (AVT) of 3.89% and 36.9%, respectively. In contrast, stepwise and controlled dye adsorption of SQ-140 followed by D-131 on mesoporous TiO2 leads to further improvement in the PCE from 3.89% to 4.50%, while AVT is reduced from 36.9% to 15.6%. This marked improvement in the PCE for the stepwise co-sensitized transparent DSSCs is attributed to the suppression of unfavorable inter-dye interaction leading to synergistic photon harvesting by both of the constituent sensitizing dyes.

DOI： https://doi.org/10.1002/pssa.202300158

DOI： https://doi.org/10.1002/pssa.202300158

Kyutacar

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300158

Vertical Distribution of Molecular Orientation and Its Implication on Charge Transport in Floating Films of Conjugated Polymers 査読有り 国際誌

Harshita Rai, Kumar Vivek Gaurav, Safalmani Pradhan, Moulika Desu, Shubham Sharma, Shuichi Nagamatsu, Shyam S. Pandey

Physica Status Solidi-A ( Wiley )   220 ( 24 )   2300236 (1) - 2300236 (7)   2023年06月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Fabrication of uniform and oriented thin films of conjugated polymers (CPs) with controlled thickness is essential for the implementation of organic devices. Over the years, unidirectional floating film transfer method (UFTM) has emerged as a facile technique for the fabrication of oriented thin films but its distribution of orientation in vertical (thickness) direction has not been explored yet. To investigate this, thin films of nonregioregular poly(3-hexylthiophene) are fabricated using UFTM with different concentrations of CPs to obtain thickness variation from 11 to 47 nm. Thin films of 4% and 9% polymer solution have similar dichroic ratio of 5.5 but have an appreciable difference in film thickness of 12 and 47 nm where thicker films are disordered as probed by polarized absorption spectra. Organic field-effect transistors fabricated using thinner films (12 nm) exhibit a saturated charge carrier mobility of 2.3 × 10−3cm2 V−1 s−1, an order of magnitude higher than its thicker (47 nm) counterpart. This difference in device performance can be attributed to the fact that charge transport is principally governed by the top polymer surface at air–polymer interface, which is found to be more disordered owing to the vertical distribution of orientation.

DOI： https://doi.org/10.1002/pssa.202300236

DOI： https://doi.org/10.1002/pssa.202300236

Kyutacar

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300236

Optimization of Device Parameters for Back Contact Transparent Conductive Oxide Less Dye Sensitized Solar Cells Fabrication 査読有り 国際誌

Md Zaman Molla, Ajay Kumar Baranwal, Shuzi Hayase, Shyam S. Pandey

Physica Status Solidi-A ( Wiley )   220 ( 4 )   2300095(1) - 2300095(7)   2023年06月

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Transparent conductive oxide–less (TCO-less) dye-sensitized solar cell (DSSC) has been constructed and characterized employing mesoporous TiO2-coated stainless-steel mesh (S-S-mesh or Mesh) as a bendable photoanode and iodine-based redox electrolyte. Efforts have been directed toward optimizing electronic parameters to enhance the power conversion efficiency (PCE) of TCO-less DSSC to equalize its TCO-based DSSC counterpart. It is found that protection of Mesh is essential for increasing the PCE of TCO-less DSSCs employing iodine electrolyte as assured by suppressed reverse saturation current and better diode factor. The PCE of 5.6% is obtained with TCO-less DSSC compared with TCO-based DSSC with PCE of 6.09%. A bit of decrease in PCE with TCO-less DSSC is due to larger resistance in TiO2/dye/electrolyte as well as within electrolyte as evident by electrochemical impedance spectroscopy (EIS) study owing to the Mesh having perforated holes and larger thickness of electrolyte absorbing sheet of the porous polytetrafluoroethylene film (35 μm) compared to TCO-based DSSC without any barriers and lower electrolyte layer thickness of 25 μm.

DOI： https://doi.org/10.1002/pssa.202300095

DOI： https://doi.org/10.1002/pssa.202300095

Design and Synthesis of Novel Squaraine Dye with Highly Enhanced Far‐Red Fluorescence and its Interaction with a Model Protein 査読有り 国際誌

Shekhar Gupta, Yuki Yamawaki, Safalmani Pradhan, Shyam S. Pandey, Tamaki Kato

Physica Status Solidi-A ( Wiley )   220 ( 24 )   2300226(1) - 2300226(8)   2023年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Novel amine-functionalized symmetrical squaraine (SQ)-dye and fluorescein isothiocyanate (FITC)–SQ–FITC dye conjugate are designed and successfully synthesized, followed by their structural and photophysical characterizations. Symmetrical SQ dye exhibits complete fluorescence quenching in polar solvents, which is explained by considering photoinduced electron transfer (PET) as a dominant quenching pathway. In contrast, FITC–SQ–FITC dye conjugate results in a decrease in an aggregation of both SQ and FITC units and about 47 times enhancement in the far-red fluorescence appearing at 674 nm. This profound enhancement in the far-red fluorescence is explained by the synergistic influence of suppression of aggregation-induced quenching (ACQ) and PET. This newly designed FITC–SQ–FITC dye conjugate shows complete quenching of the far-red fluorescence in phosphate buffer saline (PBS) owing to very strong dye aggregation, as confirmed by spectral absorption investigation. In PBS, it strongly interacts with bovine serum albumin (BSA) (Ka = 1.1 × 104 m−1) used as a model protein breaking the dye aggregation by BSA and increasing far-red fluorescence associated with SQ as a function of increasing BSA concentration. A profound 117 times increase in fluorescence at 674 nm with 25 times of BSA concentration suggests that the designed FITC–SQ–FITC is an excellent far-red probe for dye-protein interaction.

DOI： https://doi.org/10.1002/pssa.202300226

DOI： https://doi.org/10.1002/pssa.202300226

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300226

Bistable Resistive Memory Switches Fabricated by Floating Thin Films of Conjugated Polymers 査読有り 国際誌

Shubham Sharma, Nikita Kumari, Shuichi Nagamatsu, Masakazu Nakamura, Shyam S Pandey

Materials Today Electronics ( Elsevier )   4   100043(1) - 100043(1)   2023年06月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The layer-by-layer (LBL) fabrication of conjugated polymer (CPs) thin films while preserving their microstructural features by solution processing is highly desired for compact and flexible electronic circuits. However, it is cumbersome and challenging owing to the unavoidable damage to the underlying layers. To circumvent this issue, the unidirectional floating-film transfer method (UFTM) was utilized for the LBL fabrication of oriented CP thin films on the orthogonal liquid surfaces. Further, resistive bistable memory switches were fabricated by sandwiching a layer of metal nanostructures between the LBL-fabricated oriented CP thin films. The resistive switching phenomena were realized by utilizing the applied bias-dependent charge trapping, holding, and recombination on the available states at vacuum-deposited aluminum nanostructures. The effect of CP backbone conformation on the vertical charge transport was also analyzed via a comparative study of three thiophene-based polymers namely RR-P3HT, PBTTT, and PTB-7. It was revealed that CPs with relatively fewer hydrophobic side chains was more favorable for the facile vertical charge transport due to its preferred face-on conformation on the hydrophilic liquid substrate used in UFTM. It was demonstrated that a non-volatile bistable resistive memory switch fabricated using UFTM-processed oriented thin films of PTB-7 exhibited a remarkably high on-off ratio of 1.5 × 106 with high durability.

DOI： https://doi.org/10.1016/j.mtelec.2023.100043

DOI： https://doi.org/10.1016/j.mtelec.2023.100043

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S2772949423000190

Controlling the electrocatalytic activities of conducting polymer thin films toward suitability as cost-effective counter electrodes of dye-sensitized solar cells 査読有り 国際誌

Yuki Kurokawa, Takehito Kato, Shyam S. Pandey

Synthetic Metals ( Elsevier )   220   117362(1) - 117362(8))   2023年05月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Role dopant anions and solvents in electropolymerized conducting polymers (CPs) on controlling the
morphology of thin films and electrocatalytic activities to judge their suitability as low-cost counter electrodes (CE) of dye-sensitized solar cells ( DSSCs) was systematically investigated. Amongst various CPs such as polyaniline (PANI), polypyrrole (PPy), and PEDOT with sodium dodecyl sulfate (SDS) as a dopant, PEDOT was found to exhibit the best photovoltaic performance with a photoconversion efficiency (PCE) of 6.99 %. This was attributed to the best lectrocatalytic activity due to the smallest ΔEp, most minor R1, and nano-morphologyassisted high surface area, as confirmed by CV, EIS, and FE-SEM investigations. Using PEDOT as CP, the nature of dopants such as SDS, TFSI, and ClO4 has also been found to control the electrocatalytic activities and the morphology of the fabricated thin films affecting overall photovoltaic performance DSSCs. Amongst the various CP-based CE fabricated using different dopants and solvents, PEDOT:TFSI thin films prepared in acetonitrile solvent and used as CE exhibited not only the best electrocatalytic activity as CE but also demonstrated the best
photovoltaic performance with PCE of 7.0 %, which almost similar to that of DSSC utilizing Pt as CE with PCE of 7.1 %. Therefore, it was concluded that the nature of CP and dopant ions were vital factors in governing the electrocatalytic activities of the thin films to ensure their suitability as CE for optimal functioning and controlling the DSSC performance.

DOI： https://doi.org/10.1016/j.synthmet.2023.117362

DOI： https://doi.org/10.1016/j.synthmet.2023.117362

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S037967792300084X?via%3Dihub

3. Design and Synthesis of Novel NIR Sensitive Unsymmetrical Squaraine Dyes for Molecular Photovoltaics 査読有り

Safalmani Pradhan Yuki Kurokawa Shyam S Pandey

Physica Status Solidi-A ( Wiley )   220 ( 24 )   2300145(1) - 2300145(10)   2023年04月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Two novel near-infrared (NIR)-sensitive unsymmetrical squaraine dyes, SQ-258 and SQ-259, for their suitability as a sensitizer in dye-sensitized solar cells (DSSCs) are designed and synthesized, followed by photophysical and photovoltaic characterizations. It is demonstrated that introducing a 1,3-indandione acceptor unit in the central squaric acid core of SQ-259 leads to the suppression of dye aggregation owing to its nonplanar molecular geometry and the broadening of the optical absorption and photon-harvesting window up to 800 nm. Owing to the extended wavelength photon harvesting, SQ-259 improves the photoconversion efficiency (PCE) compared to its SQ-258 dye counterpart. However, despite its wide wavelength photon harvesting, the improvement in the PCE of SQ-259 is less pronounced, and this is attributed to the small driving force for injection of electrons (0.29 eV), hampered electronic coupling, and decreased electron lifetime for resistance to recombination (7.9 ms), which is confirmed by the cyclic voltammetry, quantum chemical calculation, and electrochemical impedance spectroscopic investigations, respectively.

DOI： https://doi.org/10.1002/pssa.202300145

DOI： https://doi.org/10.1002/pssa.202300145

Kyutacar

Highly Conductive Graphenated-Carbon Nanotubes Sheet with Graphene Foliates for Counter Electrode Application in Dye-Sensitized Solar Cell 査読有り 国際誌

Yusnita Yusuf, Suhaidi Shafie, Ismayadi Ismail, Fauzan Ahmad, Mohd Nizar Hamidon, Pandey Shyam Sudhir and Lei Wei

Journal of Science and Technology ( UPM, Malaysia )   31 ( 3 )   2023年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

This work enlightened the synthesis of graphenated-carbon nanotubes sheet (g-CNT) using the floating-catalyst chemical vapor deposition method (FCCVD) for dye-sensitized solar cell (DSSC) application. The carbon injection flow rate in the experiment was varied to 6, 8, and 10 ml/h. The morphological findings revealed that the g-CNT formed a highly conductive network. Excellent conductivity was obtained for the sample g-CNT8 (34.5 S/cm) compared to the sample g-CNT6 (11.2S/cm) and CNT10 (4.76 S/cm). This excellent feature is due to the hybrid structure of the g-CNT8, which creates efficient electron transfer in the materials resulting in higher conductivity. The hybrid structure provides a high surface area that improves conductivity. Therefore, the g-CNT sheet is an excellent candidate to replace the conventional platinum used as a counter electrode (CE) in DSSC.

DOI： 10.47836/pjst.31.3.12

DOI： 10.47836/pjst.31.3.12

その他リンク： http://www.pertanika.upm.edu.my/pjst/browse/prepress-issue?article=JST-3570-2022

Optical and dielectric realisation of biomolecular detection using gold nanoparticles bio-conjugate with liquid crystal 査読有り 国際誌

Lokesh K. Gangwar, Vikash Sharma, Amit Choudhary, Gajjala Sumana, Shyam .S. Pandey, Hirofumi Tanaka, Ashok M. Biradar, Rajesh

Journal of Molecular Liquids ( Elsevier )   380   121754   2023年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Dielectric biosensor based on nematic liquid crystal platform has been fabricated using sandwich immunoassay technique for the detection of a biomolecule, human cardiac troponin I (cTnI). The optical response of Liquid crystal (LC) biosensor and its corresponding frequency-dependent dielectric properties have been investigated as a function of cTnI concentration. Gold nanoparticles conjugate with detection antibody (AB-GNP) is used for the enhancement of both the optical and dielectric signal of the biosensor. AB-GNP binding with cTnI alter the surface energy of the substrate causing disturbances in LC alignment resulting in a change in transmission. The transmission of the LC cell has been found to be varying from dark to bright texture under polarized microscope as a function of cTnI concentration. A change in low-frequency permittivity with increasing cTnI concentration that forms an increasing order of sandwich immunocomplex with AB-GNP revealed an interfacial surface phenomenon. A positive shift in the onset frequency of permittivity is observed due accumulation of immunocomplex with increasing concentration of cTnI at electrode/LC interface. The dielectric response
of the biosensor is fitted with Hill-Langmuir equation over a concentration range of 0.01 to 10 ng mL−1 cTnI. The dissociation constant ‘Kd’ of 1.02 ± 0.24 ng/mL−1 indicates strong cTnI binding affinity for substrate antibody. A nearby value of 1, calculated for Hill coefficient ‘n’ revealed no co-operativity characteristic of cTnI binding to the primary capture antibody, wherein each binding site of the antibody functions independently at the electrode surface, causing accumulation of charged species revealing LC interfacial surface electrical property.

DOI： 10.1016/j.molliq.2023.121754

DOI： 10.1016/j.molliq.2023.121754

その他リンク： https://www.sciencedirect.com/science/article/pii/S0167732223005573?via%3Dihub

Bifacial Dye-Sensitized Solar Cells Utilizing Visible and NIR Dyes: Implications of Dye Adsorption Behaviour 査読有り 国際誌

Suraya Shaban, Ajendra K Vats, Shyam S Pandey

Molecules ( MDPI )   28 ( 6 )   2784   2023年03月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Bifacial dye-sensitized solar cells (DSSCs) were fabricated utilizing dye cocktails of two dyes, Z-907 and SQ-140, which have complementary light absorption and photon harvesting in the visible and near-infrared wavelength regions, for panchromatic photon harvesting. The investigation of the rate of dye adsorption and the binding strengths of the dyes on mesoporous TiO2 corroborated the finding that the Z-907 dye showed a rate of dye adsorption that was about >15 times slower and a binding that was about 3 times stronger on mesoporous TiO2 as compared to SQ-140. Utilizing the dye cocktails Z-907 and SQ-140 from ethanol, the formation of the dye bilayer, which was significantly influenced by the ratio of dyes and adsorption time, was demonstrated. It was demonstrated that the dyes of Z-907 and SQ-140 prepared in 1:9 or 9:1 molar ratios favoured the dye bilayer formation by subtly controlling the adsorption time. In contrast, the 1:1 ratio counterpart was prone to form mixed dye adsorption; the best performance of the BF-DSSCs was shown when a dye cocktail of Z-907 and SQ-140 in a molar 9:1 ratio was used to prepare a photoanode for 1 h of dye adsorption. The BF-DSSCs thus exhibited PCEs of 4.23% and 3.48% upon the front and rear side light illuminations, a cumulated PCE of 7.71%, and a very good BBF of 83%.

DOI： https://doi.org/10.3390/molecules28062784

DOI： https://doi.org/10.3390/molecules28062784

Kyutacar

その他リンク： https://www.mdpi.com/1420-3049/28/6/2784

Bioactive potential of morin loaded mesoporous silica nanoparticles: A nobel and efficient antioxidant, antidiabetic and biocompatible abilities in in-silico, in-vitro, and in-vivo models 査読有り 国際誌

Rout George Kerry, Kshitij RB Singh, Subhasis Mahari, Atala Bihari Jena, Bijayananda Panigrahi, Kahnu Charan Pradhan, Satyanarayan Pal, Bhagaban Kisan, Jagneshwar Dandapat, Jay Singh, Shyam S Pandey, Ravindra Pratap Singh, Sanatan Majhi

Open Nano ( Elsevier )   10   100126   2023年02月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Developing a delivery system has become crucial in engineering cutting-edge next-generation theranostic approaches. Therefore, in the present research work, a customized Mesoporous silica nanoparticle (MSiNPs) was designed by adapting the Stöber method with silane polymerization for Morin (MO) adsorption. The average size of MSiNPs was 50–130 nm as measured by TEM, while FE-SEM revealed a spherical surface shape. According to Raman and FTIR spectra, while the synthesis of MSiNPs, CTAB (a surfactant) was eliminated from MSiNPs, silane was functionalized, and with a loading efficiency of 10.28 ± 0.22%, MO was adsorbed. Molecular docking was used to perform in-silico studies to investigate the interaction of native MO with antidiabetic and antioxidant enzymes. Furthermore, the antioxidant and antidiabetic effects of both MO adsorbed MSiNPs, and native MO were examined in vitro, with the former showing promise even at lower concentrations than the latter. The cell survival experiment on Mouse macrophages RAW 264.7 and HCT cells revealed that MO adsorbed MSiNPs were nontoxic up to 15 μg/ml. The acute toxicity of different concentrations of MO adsorbed MSiNPs was also conducted in an in vivo model zebrafish (Danio rerio), where the study was conducted for about 96 h and evaluated for histological significance. The findings described above revealed that the MSiNPs were electrochemically, structurally, and thermally stable and MO adsorbed MSiNPs were nontoxic and biocompatible, implying that it might be an effective drug delivery vehicle for MO in the future. Moreover, in coming times, this nano-delivery system with effective biodistribution of the adsorbed MO could be explored as an antidiabetic and anti-cancer agent.

DOI： https://doi.org/10.1016/j.onano.2023.100126

DOI： https://doi.org/10.1016/j.onano.2023.100126

その他リンク： https://www.sciencedirect.com/science/article/pii/S2352952023000063

Improving vertical charge transport in organic Schottky diodes via Interface engineering of large-area conducting polymer thin films fabricated on hydrophilic liquid surface of tunable surface energy 査読有り 国際誌

Subhajit Jana, Nikita Kumari, Shyam S Pandey, Rajiv Prakash

Applied Surface Science ( Elsevier )   616   156377   2023年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Molecular orientation and stacking genre proved to be one of the decisive factors for the performance of conducting polymer (CP) based electronic devices. In this context, harnessing the key advantages of the ribbon shaped “floating-film transfer method” (FTM) along with an interfacial engineering approach has been utilized for molecular rearrangement in polymer thin-films formed on the surface of a high surface energy hydrophilic liquid mixture. In this novel subphase modified floating-film transfer method (SM-FTM), dodecyl benzene sulfonic acid (DBSA) has been used to control the molecular backbone stacking proximate to the solution-liquid interface and regioregular-poly(3-hexylthiophen-2,5-diyl) (rr-P3HT) was used as the model CP to probe the polymer-DBSA interaction. The molecular arrangements in microcrystalline domains, electronic band structures, and the evolution of surface texture at the solution-liquid interface have been investigated through multiple characterization tools. After that, the electrical performances of Schottky barrier diodes (SBDs) were studied in an ITO/P3HT/AlOx/Al sandwiched structure and a dramatic enhancement of rectification ratio up to 8.2 × 106 at ± 6 V was achieved. Further, an analytical model for SM-FTM, developed using lubrication theory and thin-film dynamics, has also been presented to elucidate the polymer spreading dynamics and the mechanism of molecular rearrangement at the interface.

DOI： https://doi.org/10.1016/j.apsusc.2023.156377

DOI： https://doi.org/10.1016/j.apsusc.2023.156377

その他リンク： https://www.sciencedirect.com/science/article/pii/S0169433223000533

Cylindrical transparent conductive oxide-free dye-sensitized solar cells with treated flat titanium sheet 査読有り 国際誌

Azwar Hayat, Ajay Kumar Baranwal, Masaki Nakamura, Fujisawa Shigeki, Shyam S Pandey, Shuzi Hayase

Journal of Photonics for Energy ( SPIE )   2022年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）


Conventional dye-sensitized solar cells (DSSCs) require two transparent conductive oxide (TCO) glasses as working and counter electrodes and are one of the most costly components posing an appreciable cost burden for production and commercialization. To circumvent this issue, we propose a TCO-free device structure utilizing titanium (Ti) sheets as a substitute for TCO. This back contact device structure not only allows the removal of the costly TCO component from the working electrode but also enhances the extent of photons absorbed by the photoanode. A flat titanium sheet with microholes (FTS-MH) was successfully applied to fabricate cylindrical TCO-free-DSSCs) with a titanium sheet as a back contact electrode. When the H2O2 surface-treated FTS-MH substrate generating dense anatase TiO2 nanosheets was used as a photoanode, there was a pronounced improvement in efficiency from 5.76% to 8.59%. This was mainly attributed to the lower interfacial resistance facilitated by improved electrical contact between the conducting FTS-MH substrate and mesoporous TiO2 layer since enhancement in the dye loading was only 8.6%.

DOI： https://doi.org/10.1117/1.JPE.12.045502

DOI： https://doi.org/10.1117/1.JPE.12.045502

その他リンク： https://www.spiedigitallibrary.org/journals/journal-of-photonics-for-energy/volume-12/issue-4/045502/Cylindrical-transparent-conductive-oxide-free-dye-sensitized-solar-cells-with/10.1117/1.JPE.12.045502.short

Controlling the molecular orientation of a novel diketopyrrolopyrrole-based organic conjugated polymer for enhancing the performance of organic field-effect transistors 査読有り 国際誌

Moulika Desu, Shubham Sharma, Kuang-Hao Cheng, Yu-Han Wang, Shuichi Nagamatsu, Jyh-Chien Chen, Shyam S Pandey

Organic Electronics ( Elsevier )   113   106691   2022年11月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

A novel organic conjugated copolymer p(DPP-BZC) was utilized as a solution-processable organic semiconductor and its large area of the unidirectionally oriented thin film was fabricated by the Ribbon-shaped floating film transfer (FTM) method. Organic field-effect transistors (OFETs) fabricated using oriented thin films of this polymer demonstrated a clear p-type semiconducting behaviour and anisotropic charge carrier transport. A maximum orientation with a dichroic ratio of 5.1 was obtained in the FTM-processed thin film under optimized condition with liquid substrate viscosity, temperature and polymer solution concentration of 6.12 cst, 50 °C and 3% (w/v), respectively. Out-of-plane XRD and in-plane GIXD results revealed that oriented thin films of this copolymer are semicrystalline and adopt purely edge-on conformation. The implication of surface modification of Si/SiO2 gate dielectric utilizing HMDS. OTS and CYTOP on the charge carrier transport revealed that substrate with high-surface-energy hampers the on/off ratio, operating voltage and charge carrier mobility (μ). On the other hand, Si/SiO2 substrate treated with CYTOP having relatively lower surface energy demonstrated the best device performance with the highest μ of 2.7 x 10−2 cm2/Vs, which is > 30 times higher as compared to that of its non-oriented spin-coated device counterparts an μ of 8.0 x 10−4 cm2/V

DOI： https://doi.org/10.1016/j.orgel.2022.106691

DOI： https://doi.org/10.1016/j.orgel.2022.106691

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S1566119922002634

Mechanical Modelling and Stress-Strain Prediction of Electroactive Polymer-Based Capacitive Sensor under Multiaxial Loads using Uniaxial Tensile Data 査読有り 国際誌

Nitin Kumar SINGH, Kazuto TAKASHIMA and Shyam S. PANDEY

Sensors and Transducers ( IFSA Publishing )   259 ( 5 )   12 - 18   2022年10月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In this paper, mechanical modelling and stress-strain prediction of the ionic type of electroactive polymer (EAP)
based capacitive strain sensor under multiaxial loading has been performed using uniaxial tensile data. A highly stretchable
sensor with > 400 % strain was fabricated using Styrene-ethylene-butylene-styrene (SEBS) rubber and Dodecyl benzene
sulphonic acid (DBSA) doped polyaniline (PANI) composite material as a dielectric film, and carbon grease as top and bottom
electrodes. From uniaxial tensile measurements, a three-dimensional constitutive model of the EAP strain sensor was validated.
Experimental data obtained from the uniaxial tensile measurement was fitted according to the Ogden-based constitutive
mathematical model. For predicting the stress-strain behaviour of the sensor under the multiaxial loads, 2nd term of the Ogden
model was demonstrated to fit well with uniaxial tensile data. Such modelling can play a significant role in designing any type
of EAP-based sensor for various operations under variable loading conditions.


その他リンク： https://www.sensorsportal.com/HTML/DIGEST/october_2022/Vol_259/P_3275.pdf

Unraveling the Implications of Macromolecular Orientation on the Planar and Vertical Charge Transport in Organic Electronic Devices 査読有り 国際誌

Shubham Sharma, Ajendra Kumar Vats, Manish Pandey, Shuichi Nagamatsu, Jyh-Chien Chen, Shyam S Pandey

ACS Applied Polymer Materials ( American Chemical Society )   4 ( 11 )   8315 - 8323   2022年10月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The role of film morphology of conjugated polymers (CPs) and their macromolecular conformation with respect to the substrate in governing charge transport and overall device performances has been a matter of debate. The nature of the macromolecular orientation of CPs in thin films has a pivotal role in controlling the performance of planar and sandwich devices. Thin-film characterizations unveiled that spin-coated films are isotropic with mixed edge-on/face-on conformation, whereas unidirectional floating film transfer method (UFTM) films are anisotropic with edge-on-oriented micrometer-sized ordered domains. To unravel the explicit role of molecular orientation on device performance, two types of devices, organic Schottky diodes (OSDs) for out-of-plane carrier transport and organic field-effect transistors (OFETs) for in-plane charge transport, were fabricated and characterized. Isotropic and relatively low crystalline spin-coated films exhibited superior transport characteristics in the out-of-plane direction than UFTM films irrespective of the crystallinity. On the other hand, edge-on-oriented UFTM thin films demonstrated remarkably enhanced in-plane charge transport with more than two orders of magnitude of enhancement in the field-effect mobility. The nature of molecular orientation of different films is significantly correlated with the performance of the OSDs and OFETs.

DOI： https://doi.org/10.1021/acsapm.2c01283

DOI： https://doi.org/10.1021/acsapm.2c01283

Kyutacar

その他リンク： https://pubs.acs.org/doi/full/10.1021/acsapm.2c01283

Synthesis and Characterization of Newly Designed and Highly Solvatochromic Double Squaraine Dye for Sensitive and Selective Recognition towards Cu2+ 査読有り

Linjun Tang, Shubham Sharma, Shyam S Pandey

Molecules ( MDPI )   27 ( 19 )   6578   2022年10月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Synthesis and characterization of a novel and zwitterionic double squaraine dye (DSQ) with a unique D-A-A-D structure is being reported. Contrary to the conventional mono and bis-squaraine dyes with D-A-D and D-A-D-A molecular frameworks reported so far, DSQ dye demonstrated strong solvatochromism allowing for the multiple ion sensing using a single probe by judicious selection of the suitable solvent system. The DSQ dye exhibited a large solvatochromic shift of about 200 nm with color changes from the visible to NIR region with metal ion sensitivity. Utilization of a binary solvent consisted of dimethylformamide and acetonitrile (1:99, v/v), highly selective detection of Cu2+ ions with the linearity range from 50 μM to 1 nM and a detection limit of 6.5 × 10−10 M has been successfully demonstrated. Results of the Benesi–Hildebrand and Jobs plot analysis revealed that DSQ and Cu2+ ions interact in the 2:1 molecular stoichiometry with appreciably good association constant of 2.32 × 104 M−1. Considering the allowed limit of Cu2+ ions intake by human body as recommended by WHO to be 30 μM, the proposed dye can be conveniently used for the simple and naked eye colorimetric monitoring of the drinking water quality.

DOI： https://doi.org/10.3390/molecules27196578

DOI： https://doi.org/10.3390/molecules27196578

その他リンク： https://www.mdpi.com/1420-3049/27/19/6578

Electronic versus Ionic Electroactive Polymers (EAPs) Strain Sensors for Wearable Electronics: A Comparative Study 査読有り

Nitin Kumar Singh, Kazuto Takashima, Shyam Sudhir Pandey

Engineering Proceedings ( Multidisciplinary Digital Publishing Institute )   21 ( 1 )   2022年08月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Electroactive polymer (EAP) strain sensors have gained appreciable attention as a potential candidate for their application in the area of soft electromechanical devices and have been widely used in soft robotics, healthcare, augmented reality, and wearable devices. In this research, a systematic comparison has been made by fabricating the electronic and ionic types of capacitive EAP strain sensors. To accomplish this, a combination of silicone rubber sandwiched between silver-coated stretchable fabric electrodes is used as an electronic type of EAP sensor, while a conducting and stretchable freestanding film consisting of Styrene-ethylene-butylene-styrene (SEBS) rubber and dedocyl benzene sulfonate acid (DBSA) doped polyaniline composite film sandwiched between carbon grease electrodes is chosen as an ionic type of EAP sensor. Mechanical characterization in terms of the uniaxial tensile testing was …

DOI： https://doi.org/10.3390/engproc2022021001

DOI： https://doi.org/10.3390/engproc2022021001

その他リンク： https://www.mdpi.com/2673-4591/21/1/1

Fabrication, characterization and modelling of the fabric electrode-based highly stretchable capacitive strain sensor 査読有り

Nitin Kumar Singh, Kazuto Takashima, Shyam S Pandey

Materials Today Communications ( Elsevier )   32   104095   2022年07月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Highly stretchable and capacitance-based strain sensors were fabricated utilizing highly stretchable silicone elastomer as dielectric film sandwiched between the conducting and stretchable cloth-based top and bottom electrodes. Electromechanical characterizations for the proposed sensor after multiple and reversible loading and unloading cycles up to 150% applied strain were conducted followed by the modelling of the sensing performance. It has been shown that the sensor exhibits reproducible electromechanical performance under multiple reversible stretching and relaxation cycles. There was a very small deviation (< 10%) in the observed values of the capacitance upon the applied strain of 150% up to the 1000 loading and unloading cycles. Tensile measurement for the sensor under various applied strains, not only exhibits almost constant force indicating negligible Mullins effect and negligible time-dependent changes at a fixed strain up to 100% suggesting that viscoelastic losses can also be neglected. From uniaxial tensile experiments, constitutive model of the dielectric elastomer sensor was validated. For the fitting of the experimental data obtained from the uniaxial tensile measurement, a variety of strain energy formulations have been compared for predicting the constitutive behaviour of sensor using the Mooney– Rivlin, Neo-Hookean, Yeoh and Ogden models, where 2nd term of the Ogden model was found to explain the experimental tensile data most accurately. To explain some observed losses at 150% of applied strain, the Prony series-based time dependent model was used for predicting stress at any value of time and it was found that experimental data was well fit with 4th order of Prony series.

DOI： https://doi.org/10.1016/j.mtcomm.2022.104095

DOI： https://doi.org/10.1016/j.mtcomm.2022.104095

その他リンク： https://www.sciencedirect.com/science/article/pii/S2352492822009473

Fabrication and Characterization of Oriented Thin Films of DPP-based Conjugated Copolymer Prepared by Friction Transfer Method 査読有り

Yuki Kurokawa, Ajendra K Vats, Shuichi Nagarnatsu, Shyam S Pandey

IEEE Explore ( IEEE )   124 - 127   2022年07月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Japan   http://www.amfpd.jp/   2022年07月05日  -  2022年07月08日

DOI： 10.23919/AM-FPD54920.2022.9851297

DOI： 10.23919/AM-FPD54920.2022.9851297

その他リンク： http://www.amfpd.jp/

Interplay of viscosities in controlling the orientation of conjugated polymer thin films fabricated by floating film transfer method 査読有り

Shubham Sharma, Ajendra K Vats, Shuichi Nagamatsu, Shyam S Pandey

IEEE Explore ( IEEE )   116 - 119   2022年07月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Japan   http://www.amfpd.jp/   2022年07月05日  -  2022年07月08日

DOI： 10.23919/AM-FPD54920.2022.9851340

DOI： 10.23919/AM-FPD54920.2022.9851340

その他リンク： http://www.amfpd.jp/

Tear strength estimation of electroactive polymer-based strain sensors 査読有り

Nitin Kumar Singh, Kazuto Takashima, Shyam Sudhir Pandey

Electroactive Polymer Actuators and Devices (EAPAD) XXIIV ( SPIE )   12042   424 - 428   2022年04月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

USA   https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12042/1204217/Tear-strength-estimation-of-electroactive-polymer-based-strain-sensors/10.1117/12.2627807.short  

Electroactive polymer-based sensors are subjected to repeated loading and unloading cycles under variable applied strains and estimation of the tear strength plays a critical role in determining durability. A trouser type of specimen made from conducting and stretchable freestanding films consisting of SEBS rubber and dodecyl benzenesulfonic acid (DBSA) doped polyaniline composite was used for fabricating the capacitive strain sensor and tear strength estimation. Strain energy density for the composite film was calculated from the tear test data aiming towards the prediction of the life of the specimen. Our results revealed a very high value (150 newton/mm) of tear strength, leading to the sustainability of the film up to millions of cycles.

DOI： https://doi.org/10.1117/12.2627807

DOI： https://doi.org/10.1117/12.2627807

その他リンク： https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12042/1204217/Tear-strength-estimation-of-electroactive-polymer-based-strain-sensors/10.1117/12.2627807.short

Computational molecular design of NIR dyes with varying anchoring groups for improving the efficiency and stability of dye-sensitized solar cells 査読有り 国際誌

Pandey S.S., Vats A.K., Tang L., Hayase S.

Japanese Journal of Applied Physics   61 ( SB )   SB1021-1 - SB1021-11-   2022年01月

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Design and development of near-infrared (NIR) dyes with strong binding on the TiO2 surface is inevitable for the realization of the dye-sensitized solar cells (DSSCs) with improved efficiency and stability. A series of NIR dyes bearing different anchoring groups have been designed considering their suitability as sensitizers for DSSCs based-on TiO2 and iodine-based redox electrolytes. Under the Gaussian program, density functional theory (DFT)/6-311G/B3PW91 level of theory and time-dependent-DFT using the polarizable continuum model is shown optimum for the prediction of the highest occupied molecular orbital energy level and electronic absorption spectra. The reliability of the calculated results was validated by corresponding experimental results for some of the representative dyes. It has been demonstrated that λ max at full width at half maximum in calculated absorption spectra exhibited an excellent match with the experimentally estimated Eg of the sensitizers leading to the proposal of a new method for the construction of the theoretical energy band diagram. Amongst newly designed sensitizers, dyes bearing dual anchoring groups like SQ-149, SQ-150, SQ-158, SQ-161 and SQ-162 are highly promising not only for good NIR photon harvesting but also to impart to improved DSSC stability.

DOI： 10.35848/1347-4065/ac28e8

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85125598296&origin=inward

Charge transfer and catalytic properties of various PEDOTs as Pt-free counter electrodes for dye-sensitized solar cells 査読有り 国際誌

Yuki Kurokawa, Ajendra Kumar Vats, Takehito Kato, Suhaidi Shafie, Shyam S. Pandey

Japanese Journal of Applied Physics   61 ( SB )   SB1010-1 - SB10110-6   2022年01月

　詳細を見る

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Despite the high electrocatalytic activity of Pt and the fact it is a champion catalyst for the counter electrode (CE) of state-of-art dye-sensitized solar
cells (DSSCs), its high cost, rarity, and the concern about its possible deterioration by the iodine-based redox electrolyte, has compelled the search
for suitable and low-cost catalysts for CEs. To circumvent this issue, efforts were directed to exploring the suitability of various types of poly(3,4-
ethylenedioxythiophene)(PEDOT)-based conducting polymers as the most suitable electrocatalysts for low-cost CEs. Amongst various types of
PEDOT explored as CEs, micelle directed electropolymerized PEDOT:SDS (:sodium dodecyl sulfate) exhibited not only excellent catalytic activity
(>Pt), as confirmed by cyclic voltammetry and electrical impedance spectroscopy investigations, but also fairly good photovoltaic performance
exhibiting photoconversion efficiency of 5.8%, which is only slightly lower than the performance shown by Pt-based CE for the DSSCs fabricated
under similar experimental conditions. Further improvement for the PEDOT:SDS-based CE surpassing the Pt-based CE is envisioned by
morphological control and making their suitable composites with carbon-based nanomaterials.

DOI： https://doi.org/10.35848/1347-4065/ac2cf8

DOI： https://doi.org/10.35848/1347-4065/ac2cf8

その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/ac2cf8

Bifacial dye-sensitized solar cells utilizing green colored NIR sensitive unsymmetrical squaraine dye 査読有り 国際誌

Suraya Shaban, Pritha Roy, Ajendra K. Vats and Shyam S. Pandeyy

Japanese Journal of Applied Physics   61 ( SB )   SB1005-1 - SB1005-6   2022年01月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Dye-sensitized solar cells (DSSCs) with the capability of photon harvesting from both front and rear sides, consisting of newly developed NIR dye
(SQ-140), iodine-based redox electrolyte, and transparent counter electrode with high bifaciality factor (BFF) and good cumulated photoconversion
efficiency (PCE), are successfully fabricated and characterized. The use of transparent TiO2-based photoanode leads to improved BFF as
compared to its opaque TiO2 counterparts: from 74% to 86% under similar experimental conditions and device parameters. The high molar
extinction coefficient of the NIR dye SQ-140, needing a thinner TiO2 layer, was found to be advantageous to maintaining the high BFF even in
thicker TiO2 films without serious compromise in the PCE. The lower efficiency of the bifacial DSSC under rear illumination was attributed to the
hampered optical penetration as well as absorption of light by the intense colored iodine-based redox electrolyte.

DOI： https://doi.org/10.35848/1347-4065/ac3570

DOI： https://doi.org/10.35848/1347-4065/ac3570

その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/ac3570

Recent progress in the macroscopic orientation of semiconducting polymers by floating film transfer method, 査読有り 国際誌

Manish Pandey, Vipul Singh, Chandan Kumar, Shyam S. Pandey, and Masakazu Nakamura

Japanese Journal of Applied Physics   61 ( SB )   SB0801-1 - SB0801-12   2022年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Orienting semiconducting polymers (SCPs) using solution-processable techniques for organic electronic devices is essential for realizing a
printable electronics device. Preparation of oriented films on liquid substrates and transferring on actual device substrate offers many advantages,
including layer-by-layer coating, independent control of morphology, freedom to choose substrates, and device geometry. The floating films transfer
method (FTM) has emerged as a unique method to prepare oriented films of SCP using solution processing. Here, we review recent progress in
this method from the viewpoint of improvement in FTM to orient SCPs and their anisotropy in organic field effect transistors. In addition, the use of
FTM films in sensing applications is also reviewed.

DOI： https://doi.org/10.35848/1347-4065/ac2f20

DOI： https://doi.org/10.35848/1347-4065/ac2f20

その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/ac2f20

A COMPARATIVE STUDY OF GRAPHENATED-CARBON NANOTUBES COTTON AND CARBON NANOTUBES AS CATALYSTS FOR COUNTER ELECTRODE IN DYE-SENSITIZED SOLAR CELLS 査読有り 国際誌

Yusnita Yusuf, Suhaidi Shafie, Ismayadi Ismail, Fauzan Ahmad, Mohd Nizar Hamidon, Shyam S Pandey, Nazalea Yazmin Muhammad, Wei Lei

Malaysian Journal of Microscopy   2021年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

This work reports a comparative study of synthesized graphenated-carbon nanotubes cotton (g-CNTC), standard carbon nanotubes (CNTP), and conventional platinum (Pt) thin layer which are employed as the counter electrodes in dye-sensitized solar cells (DSSC). The g-CNTC was synthesized via the floating-catalyst chemical vapor deposition (FCCVD) method. Subsequently, the g-CNTC was made into a uniform paste and deposited for the counter electrode layer. The results obtained from FESEM/TEM, Raman spectroscopy, CV and I-V measurements respectively exposed the structural, graphitization and I-V characteristics. Briefly, the morphology of g-CNTC showed the growth of graphene foliates out-sidewalls of CNT with a diameter of 40 nm. The graphitization of g-CNTC showed two dominant peaks namely the D (1355 cm-1) and G (1608 cm-1) bands with strong intensities. The g-CNTC counter electrode provided good electrical conductivity (3.66×10-3 to 6.45×10-3 S/cm), which is a significant feature to employ counter electrodes to enhance DSSC performance. In addition, the g-CNTC counter electrode offered an excellent catalytic activity for iodide/triiodide reaction and exhibited 3.49 % of photovoltaic conversion energy, which was much higher compared to CNTP (2.93 %) and platinum (3.12 %), respectively.

その他リンク： https://malaysianjournalofmicroscopy.org/ojs/index.php/mjm/index

Highly sensitive organic phototransistors fabricated from PCPDTBT: PCBM blend 査読有り 国際誌

Yadav N., Kumari N., Ando Y., Pandey S.S., Singh V.

Journal of Physics: Conference Series   2070 ( 1 )   2021年11月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Organic phototransistors (OPTs) play a crucial role in various light sensing and imaging applications. In this work, we have fabricated highly sensitive Poly[2,6-(4,4-bis-(2ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT)/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blended thin film based OPTs using ribbon-floating film transfer method. A high charge carrier mobility (µ) of 0.002 cm2V-1s-1 and an Ion/Ioff of 6 × 104 was showcased by the blended polymer thin film based OPT as compared to its pristine polymer thin film based counterpart which had a µ of 0.001 cm2V-1s-1 and an Ion/Ioff of 9 × 103. Further, the blended polymer thin film based OPT demonstrated a high photosensitivity of 6.6 × 103 and a photoresponsivity of 0.13 A/W towards white light which were much superior than those of many of the previously reported polymer thin film based OPTs. The results hold crucial significance towards the development of cost effective blended polymer thin film based OPTs.

DOI： 10.1088/1742-6596/2070/1/012040

Scopus

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Implication of color of sensitizing dyes on transparency and efficiency of transparent dye-sensitized solar cells 査読有り 国際誌

Roy P., Vats A.K., Tang L., Pandey S.S.

Solar Energy   225   950 - 960   2021年09月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Dye-sensitized solar cells (DSSCs) are one of the potential candidates for the fabrication of colourful and see-through solar cells for energy harvesting esthetic windows. However, a trade-off between transparency and power conversion efficiency (PCE) has to be tackled amicably to realize the solar cells with good PCE and transparency. Judicious selection of dyes to bypass the light absorption in the high eye-sensitivity region (500–600 nm) is one of the plausible solutions. This was demonstrated utilizing yellow (D-131) and red (N-719) commercial dyes along with newly developed blue (SQ-138) and green coloured (SQ-140) dyes with intense and sharp light absorption mainly in the far-red to near-infrared (NIR) wavelength region. Transparent DSSCs fabricated using the most commonly used red-coloured dye N-719 although exhibited an increase in the PCE from 2.9% to 5.3% upon increasing the thickness of the transparent TiO2 layer from 4 μm to 10 μm but resulted in a serious loss in the average visible transparency (AVT) from 58.6% to 7.3% making the DSSC non-transparent. Contrary to this, under similar thickness variations, dyes D-131, SQ-138 and SQ-140 exhibiting very high AVT of >70% maintained the AVT > 40%, which is necessary for good visual perception.

DOI： 10.1016/j.solener.2021.08.014

Scopus

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Investigation of Orientation in the Thin Films of Conjugated Polymer and NIR Dye Blends Fabricated by Friction Transfer Method 査読有り

Yuki Kurokawa, Shuichi Nagamatsu, Shyam S Pandey

IEEE Explore ( IEEE )   2021年08月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Japan   Conference: 28th International Workshop on Active Matrix, Flatpanel Displays and Devices (AM-FPD21)A   2021年06月29日  -  2021年07月02日

Improved film’s crystallinity and facile charge transport has been well demonstrated by orienting conjugated polymers using solution based thin film fabrication followed by thermal annealing, need for huge halogenated solvents and high temperature annealing are stumbling block for industrially viable large area thin film fabrication. Herein, we report the fabrication of oriented thin films regioregular P3HT by solvent-free friction transfer (FT) technique and enhancement its further enhancement by adding NIR sensitive squaraine dyes. Apart from assisting the molecular orientation of P3HT, it has been demonstrated that dye molecules are also get oriented and a synergistic match between the alkyl chains of the polymer and dye molecule leads to promotion for the extent of the molecular orientation in the dye molecules.

DOI： 10.23919/AM-FPD52126.2021.9499214

その他リンク： https://ieeexplore.ieee.org/document/9499214

Extreme Orientational Uniformity in Large-Area Floating Films of Semiconducting Polymers for Their Application in Flexible Electronics 査読有り

Manish Pandey, Heriyanto Syafutra, Nikita Kumari, Shyam S. Pandey, Ryo Abe, Hiroaki Benten, and Masakazu Nakamura

ACS Applied Materials & Interfaces ( American Chemical Society )   2021年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Layer-by-layer fabrication of uniformly oriented thin films over large areas by cost-effective solution-based approaches can open new horizons for the realization of high-performance organic circuits in various applications. In this work, fabrication of a large-area ≈40 cm2 film with uniform orientation is reported for poly(3,3‴-dialkylquaterthiophene) (PQT) using a unidirectional floating film transfer method (UFTM). Orientation characteristics and charge transport anisotropy were analyzed using polarized UV–vis spectral mapping and fabrication of bottom-gated organic field-effect transistors (OFETs) from different regions. Films were found to be highly oriented with an optical dichroic ratio of ca. 15. Orientation characteristics reveal that films were highly oriented along the width of the film, covering >70% of the area, and angle-dependent field-effect mobilities are in good agreement with the orientation of the polymer backbones. These highly oriented films resulted in charge transport anisotropy of 8.9. An array of bottom-gated OFETs fabricated along the length of single large-area (≈15 × 2.5 cm2) thin film demonstrated the average field-effect mobility of 0.0262 cm2/(V s) with a very narrow standard deviation of 12.6%. We also demonstrated that film thickness can be easily tuned from 5.6 to 45 nm by increasing the PQT concentration, and field-effect mobility is highly reproducible even when the film thickness is 10 nm. Microstructural characterization of the thus-prepared large-area thin films revealed the edge-on stacked polymer backbones and surface roughness of <1 nm as probed by grazing incidence X-ray diffraction and atomic force microscopy, respectively. Flexible OFETs with bottom-gate top-contact geometry were also fabricated, having average field-effect mobility of 0.0181 cm2/(V s). There was no considerable change in mobility after bending the flexible devices at different radii.

DOI： 10.1021/acsami.1c09671

その他リンク： https://pubs.acs.org/doi/abs/10.1021/acsami.1c09671

Assisted alignment of conjugated polymers in floating film transfer method using polymer blend 査読有り

Heriyanto Syafutra, Manish Pandey, Nikita Kumari, Shyam S Pandey, Hiroaki Benten, Masakazu Nakamura

Thin Solid Films ( Elsevier )   734   138814(1) - 138814(8   2021年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Orientating conjugated polymers (CPs) in thin films is an attractive technique for obtaining anisotropic properties, resulting in improved device performances. Template-assisted alignment using pre-patterned substrates has been widely used to orient various polymers irrespective of their orientation capability. In this work, we report that using the floating film transfer method, the orientation of guest polymers can be in-situ assisted via blending with a host polymer during film fabrication. Dichroic Ratio (DR) of two guest CPs such as poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno[3,2-b]thiophene)] and poly(9,9-di-n-octylfluorenyl-2,7-diyl) were found to be enhanced when blended with host polymer poly(3,3‴-didodecyl-quaterthiophene) (PQT). DR of the host PQT decreases monotonically with an increase in the guest polymer proportion, suggesting that guest polymers are well mixed in the host matrix. The electronic absorption spectra and atomic force microscopy results revealed that blended polymers were well mixed without any phase separation. DR of the guest polymers in the blend was the same even when the overall blend concentration was increased twice to increase the overall film thickness.

DOI： 10.1016/j.tsf.2021.138814

その他リンク： https://www.sciencedirect.com/science/article/pii/S0040609021002972

Development of High-Sensitivity Poly (2, 7-(9, 9-dioctylfluorene)-alt-5, 5-(4', 7'-di-2-thienylbenzo [c][1, 2, 5] thiadiazole)) Thin-Film-Based Phototransistors by the Ribbon-Floating Film Transfer Method 査読有り 国際誌

Nidhi Yadav, Nikita Kumari, Yoshito Ando, Shyam S. Pandey, and Vipul Singh

Physica Status Solidi (RRL) - Rapid Research Letters ( WILEY-V CH VERLAG GMBH )   2021年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Alignment of polymer chains hold key to development of highly functional polymer based field effect transistors. Our recently developed ribbon-floating film transfer method (ribbon-FTM) has the potential for development of polymer thin films with highly aligned chains which are desirable for fabrication of efficient planar devices. These thin films consisting of well aligned polymer chains exhibit high degree of optical and electronic anisotropies. In this work we report ribbon-FTM processed thin film based organic photosensitive transistors of PFO-DBT. Under optimized fabrication conditions polymer FETs based on PFO-DBT demonstrated a charge carrier mobility of 0.002 cm²/Vs and an on-off ratio of 5 × 10⁴ under dark conditions. The devices have further demonstrated a Photosensitivity of ∽10⁴ and 10³ and a high Responsivity of 8.37 A/W and 4.6 A/W against green and red light illuminations, respectively. The results hold promise for development of conducting polymer based high performance photosensitive OFETs. This article is protected by copyright. All rights reserved.

DOI： 10.1002/pssr.202100185

その他リンク： https://onlinelibrary.wiley.com/doi/epdf/10.1002/pssr.202100185

Probing the metal/conducting polymer interface and implications of the metal diffusion in two-terminal sandwich devices 査読有り 国際誌

Nidhi Yadav, Nikita Kumari, Yoshito Ando, Shyam S Pandey, Vipul Singh

Synthetic Metals ( Elsevier )   278   116797(1) - 116797(11)   2021年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

In this article, we have investigated the role of polymer regio-regularity and film fabrication technique in reducing metal diffusion from top electrodes in sandwich type devices. Poly(3-hexyl thiophene)(P3HT) polymer of varying regio-regularity was chosen for investigation and its corresponding thin films were fabricated by spin-coating(SC) and floating film transfer method(FTM). Sandwich devices with a top interface between gold and i) FTM coated regio-regular (rr) P3HT, ii) FTM coated non-regiocontrolled (nr) P3HT, iii) SC nr-P3HT and iv) SC rr-P3HT were fabricated. The current density vs voltage (J-V) characteristics of the devices revealed non-ohmic characteristics. Estimation of interfacial hole barrier heights using Fowler Nordheim tunneling model revealed a small barrier of 1.12 eV for the isotropic spin-coated nr-P3HT film which increased to 1.37 eV with an increase in film anisotropy for the FTM nr-P3HT film. The barrier height also gradually declined from 1.37 eV to 1.05 eV with increase in regioregularity from FTM nr-P3HT to FTM rr-P3HT. These observations were confirmed through optical and structural characterizations along with depth profiling of metal diffusion using XPS. Pronounced Au diffusion to a higher depth was observed in the XPS results for the highly anisotropic FTM film that decreased subsequently with decrease in anisotropy from FTM to spin-coated film. It was thus deduced that a judicious selection of fabrication technique and polymer aids in reducing metal diffusion leading to improved device performance. The results hold crucial significance towards the fabrication of efficient organic photodetectors that have a sandwich type device architecture.

DOI： 10.1016/j.synthmet.2021.116797

その他リンク： https://www.sciencedirect.com/science/article/pii/S0379677921001028

Development of PCPDTBT thin film based highly sensitive organic phototransistors 査読有り 国際誌

Nidhi Yadav, Nikita Kumari, Shyam S Pandey, Vipul Singh

Materials Today' Proceeding ( Elsevier )   2021年04月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In this report, we have proposed a novel ribbon-FTM method to develop highly oriented polymer thin films. A donor–acceptor (D-A) type copolymer, PCPDTBT has been selected as the target material for investigation. The maximally oriented film showcased a DR of 4.1. Highly aligned polymer film was used as the active layer for the development of bottom gate bottom contact (BGBC) type OFETs. An average mobility and an Ion/Ioff of 0.002 cm2/Vs and 5 × 103 were obtained under dark conditions, respectively. Upon illumination with monochromatic green light (λ = 522 nm, Pin = 0.5 mW/cm2), the OPTs showcased a high photosensitivity and responsivity of 103 and 17 A/W, respectively. The obtained values were found to be superior over many of the previously reported similar OPTs which employed other organic polymers. The results thus are of crucial significance with respect to the development of facile, cost effective and highly sensitive single polymer thin film based OPTs.

DOI： 10.1016/j.matpr.2021.03.468

その他リンク： https://www.sciencedirect.com/science/article/pii/S2214785321025232?via%3Dihub

Fatigue life prediction of electroactive polymer strain sensor 査読有り

Nitin Kumar Singh, Kazuto Takashima, Shyam Sudhir Pandey

Electroactive Polymer Actuators and Devices (EAPAD) XXIII ( International Society for Optics and Photonics )   11587   115871Z(1) - 115871Z(7)   2021年03月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

USA   Sandiego, California   2021年03月22日  -  2021年03月27日

Electroactive polymers strain sensors bear a great potentiality in the area of soft robotics, wearable devices, and fitness industries. A small initial defect present in such sensor may grow to a critical size during contraction and relaxation cycles leading to mechanical failure, therefore, prediction of fatigue life is inevitable. The crack growth approach is one of the amicable ways to estimate the fatigue life considering parameters like tear energy, crack geometry, and power law. In this work, crack growth approach based on power law is being proposed to predict fatigue life utilizing conducting and stretchable freestanding films consisted of SEBS rubber and dodecyl benzenesulfonic acid (DBSA) doped polyaniline composite. Utilizing this crack growth model for the prediction of fatigue life exhibited that such films can sustain more than a million cycles even at a large value of deformation.

DOI： 10.1117/12.2584521

その他リンク： https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11587/115871Z/Fatigue-life-prediction-of-electroactive-polymer-strain-sensor/10.1117/12.2584521.short

PCPDTBT copolymer based high performance organic phototransistors utilizing improved chain alignment 査読有り 国際誌

Nidhi Yadav, Nikita Kumari, Yoshito Ando, Shyam S Pandey, Vipul Singh

Optical Materials ( Elsevier )   113   110886(1) - 110886(9)   2021年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

In this article, we report single component thin film based organic phototransistors (OPTs) developed using the novel ribbon-floating film transfer method (ribbon-FTM). A low band-gap copolymer, poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) has been employed to develop the photoactive thin films of the devices. The fabricated polymer films were highly anisotropic in nature. To investigate the effect of film anisotropy on the device performance, organic field effect transistors (OFETs) were fabricated in two configurations namely, parallel and perpendicular, wherein the polymeric chains were oriented in line and orthogonal to the transistor channel direction, respectively. Notable differences in charge carrier mobility and device on-off ratios were observed among the two sets of devices. An on-off ratio of 4.1 × 103 and an average mobility of 0.001 cm2/V were observed in case of the perpendicular oriented OFETs which were increased to 105 and 0.003 cm2/V for the parallel oriented OFETs. A probe into the contact resistance at the respective metal/polymer interfaces of the devices was carried out using the modified transmission line method (MTLM). 4 times lower contact resistance was observed in the parallel OFET which was anticipated to be responsible for its superior performance. Further, the fabricated devices were illuminated with monochromatic red light (Pin = 0.4 mW/cm2) to observe their performance as phototransistors. Appreciable values of photosensitivity (2 × 104) and photoresponsivity (17.6 A/W) were obtained for the parallel OPTs which were found to be much higher than those of the previously reported thin film based OPTs employing other materials fabricated through conventional film coating techniques. The results presented in this report are of key significance towards the development of highly sensitive and cost-effective phototransistors which can be used in opto-sensing and imaging applications.

DOI： 10.1016/j.optmat.2021.110886

その他リンク： https://www.sciencedirect.com/science/article/pii/S0925346721000872

Unravelling the bottleneck of phosphonic acid anchoring groups aiming toward enhancing the stability and efficiency of mesoscopic solar cells 査読有り 国際誌

Vats A.K., Roy P., Tang L., Hayase S., Pandey S.S.

Frontiers of Chemical Science and Engineering   16 ( 7 )   1060 - 1078   2021年01月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Novel near-infrared sensitizers with different anchoring groups aiming toward improved stability and efficiency of dye-sensitized solar cells were synthesized. Adsorption of these dyes on the mesoporous TiO2 surface revealed the dye adsorption rate of −CH=CH-COOH (SQ-139) > −CH=C(CN)COOH (SQ-140) > −PO3H2 (SQ-143) > −CH=C(CN)PO3H2 (SQ-148) > −CH=C(CN) PO3H-C2H5 (SQ-157) > −PO3H-C2H5 (SQ-151) > −CH=CH-COOH(−PO3H2) (SQ-162). The binding strength of these dyes on mesoporous TiO2 as investigated by dye desorption studies follows SQ-162 > SQ-143 > SQ-148 > SQ-139 ≫ SQ-157∼SQ-151 ≫ SQ-140 order. The acrylic acid anchoring group was demonstrated to be an optimum functional group owing to its fast dye adsorption rate and better binding strength on TiO2 along with good photoconversion efficiency. Results of dye binding on TiO2 surface demonstrated that SQ-162 bearing double anchoring groups of phosphonic and acrylic acid exhibited > 550 times stronger binding as compared to dye SQ-140 having cyanoacrylic acid anchoring group. SQ-140 exhibited the best photovoltaic performance with photon harvesting mainly in the far-red to near-infrared wavelength region having short circuit current density, open-circuit voltage and fill factor of 14.28 mA·cm−2, 0.64 V and 0.65, respectively, giving the power conversion efficiency of 5.95%. Thus, dye SQ-162 not only solved the problem of very poor efficiency of dye bearing only phosphonic acid while maintaining the extremely high binding strength opening the path for the design and development of novel near-infrared dyes with improved efficiency and stability by further increasing the π-conjugation. [Figure not available: see fulltext.]

DOI： 10.1007/s11705-021-2117-z

Scopus

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Investigation of Orientation in the Thin Films of Conjngated Polymer and NIR Dye Blends Fabricated by Friction Transfer Method 査読有り 国際誌

Kurokawa Y., Nagamatsu S., Pandey S.S.

Proceedings of AM-FPD 2021 - 28th International Workshop on Active-Matrix Flatpanel Displays and Devices: TFT Technologies and FPD Materials   96 - 99   2021年01月

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Improved film's crystalhmty and facile charge transport has been well demonstrated by onenting conjugated polymers using solution based thin film fabncation followed by thermal annealing, need for huge halogenated solvents and high temperate annealing are stfnnbling block for industnally viable large area thin film fabrication Herein, we report the fabncation of oriented thin films regioregularP3HT by solvent-free friction transfer (FT) technique and enhancement its further enhancement by adding MR sensitive squaraine dyes. Apart from assisting the molecular onentation of P3HT, it has been demonstrated that dye molecules are also get onented and a synergistic match between the alkyl chainsof the polymer and dyemolecule leads to promotionfor the extentofthe molecular onentation in the dye molecules.

Scopus

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Solvent-Assisted Friction Transfer Method for Fabricating Large-Area Thin Films of Semiconducting Polymers with Edge-On Oriented Extended Backbones 査読有り

Kumari N., Pandey M., Syafutra H., Nagamatsu S., Nakamura M., Pandey S.S.

ACS Applied Materials and Interfaces   12 ( 49 )   55033 - 55043   2020年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© Recent past has witnessed huge scientific efforts aiming toward enhancing in-plane charge transport by unidirectional orientation of conjugated polymer (CP) backbones adopting various techniques. However, in most of the existing methods, excess amounts of toxic halogenated solvents and preaggregation in solution are inevitable, which are the main bottlenecks toward large-scale fabrication. Solvent-assisted friction transfer (SAFT) is being reported as a novel method and improvisation over conventional friction transfer to expand its versatility. In this method, application of a small amount of the solvent (∼3 μL) during drawing not only leads to the entirely changed film morphology and molecular orientation but also addresses the existing substrate compatibility issues. Utilizing poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]-thiophene] as a representative CP under SAFT technique, films with extended backbone and edge-on orientation was successfully fabricated, which was confirmed by various characterization tools such as X-ray diffraction, polarized absorption, and polarized Raman spectroscopies. Further, anisotropic charge transport in these films was investigated by fabricating organic field-effect transistors and the role of contact resistance was also studied. Slight solvent use, compatibility with various substrates, and film fabrication with controlled orientation, and after validation of its generality on different CPs, SAFT can be expected to open new avenues in the area of printed electronics.

DOI： 10.1021/acsami.0c14874

Scopus

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Comprehensive performance analysis of dye-sensitized solar cells using single layer TiO<inf>2</inf> photoanode deposited using screen printing technique 査読有り

Khalifa A., Shafie S., Hasan W.Z.W., Lim H.N., Rusop M., Pandey S.S., Vats A.K., AlSultan H.A., Samaila B.

Optik   223   2020年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020 Elsevier GmbH A single-layer N719 sensitized nanocrystalline TiO2 films have been successfully deposited on FTO-coated glass substrates using the screen-printing technique with four different thicknesses (10, 12, 14 and 18 μm) and used as simple and low cost photoanodes for dye-sensitized solar cells (DSSCs). The thickness was controlled by adjusting the distance between the screen-printing mesh and the FTO-coated substrate using the two height control bolts. The films were deposited using one-time screen-printing method. So that the multiple screen-printing and annealing cycles can be reduced. Furthermore, the cell fabrication time was reduced as well as the problem of recombination at the interfacial layers between the TiO2 films was avoided. The thickness of the TiO2 films was measured by the surface profilometer. The prepared photoanode samples were characterized using FESEM, EDX, AFM, and UV–vis-NIR spectroscopies. The ruthenium dye soaking time was optimized at 48 h. The photovoltaic parameters such as short circuit current density (Isc), open-circuit voltage (Voc), fill factor (FF) and power conversion efficiency (η) were measured for fabricated cells at room temperature under one sunlight 100 mW/cm2 illumination using the solar simulator. The effect of TiO2 film thickness on the fabricated DSSCs performance parameters was studied. DSSC devices with average thickness 12μm achieved the highest conversion efficiency of 5.13 % with Jsc = 12.12 mA/cm2, and Voc = 0.69 V. The obtained results revealed that the amount of the adsorbed dye increases with the increase in the TiO2 film thickness and thus improve photogenerated current. However, exceeding the optimum photoanode thickness results in decline in the photogenerated current and the overall efficiency due to back electrons recombination and the lower photoanode transmittance.

DOI： 10.1016/j.ijleo.2020.165595

Scopus

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Ordered arrangement of F4TCNQ anions in three-dimensionally oriented P3HT thin films 査読有り

Nagamatsu S., Pandey S.S.

Scientific Reports   10 ( 1 )   2020年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020, The Author(s). An ordered arrangement of electron-accepting molecular dopant, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), in three-dimensionally (3D) oriented poly(3-hexylthiophene) (P3HT) film was clarified. The 3D oriented P3HT thin films prepared by the friction-transfer technique were doped with F4TCNQ by dipping into an acetonitrile solution. The presence of F4TCNQ anions in the 3D oriented P3HT thin films was investigated by polarized ultraviolet/visible/near-infrared absorption spectroscopy, grazing incidence X-ray diffractometry, polarized Fourier transform infrared spectroscopy (FT-IR), and infrared p-polarized multiple-angle incidence resolution spectroscopy (pMAIRS). The F4TCNQ-doped 3D oriented P3HT films showed anisotropic properties in all characterizations. In particular, the anisotropic molecular vibrations from polarized FT-IR and pMAIRS have clearly revealed orientations of polymeric chains and molecular dopant molecules. Considering the results from several independent techniques indicated that F4TCNQ anions in the 3D oriented P3HT were orderly arranged in a 3D manner with respect to the 3D oriented P3HT such that their molecular long-axis parallel to the P3HT backbone, with in-plane molecular orientation. Additionally, the direction of the optical transition moment of the F4TCNQ anion was found to be parallel to the molecular short-axis.

DOI： 10.1038/s41598-020-77022-0

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Effect of electrolyte for back contact transparent conducting oxide-less dye-sensitized solar cells: Iodine versus cobalt 査読有り

Molla M.Z., Baranwal A.K., Hayase S., Pandey S.S.

Journal of Photonics for Energy   10 ( 4 )   2020年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020 Society of Photo-Optical Instrumentation Engineers (SPIE). Grätzel solar cells are reported in a transparent conducting oxide-less (TCO-less) back-contact dye-sensitized solar cell (BC-DSC) architecture using a stainless steel mesh-protected working electrode along with nanoporous TiO2 semiconductor and metal-free D205 dye. Liquid electrolytes play a significant role for the dye regeneration in the working operation of TCO-less BC-DSCs; therefore, we report the effectiveness of two different commonly utilized electrolytes (iodine-and cobalt-based redox shuttles) for the construction and performance of TCO-less dye-sensitized solar cells (DSCs). Differential performance of DSCs thus fabricated was interpreted utilizing impedance spectral and lifetime analysis. It was found that although utilization of cobalt bipyridyl complex-based electrolyte was able to harvest higher photons in the lower wavelength region (330 to 430 nm) as compared to its iodine electrolyte counterparts, hampered dye regeneration due to reduced driving force and slower ion diffusion in combination with higher charge transport resistance at TiO2 / dye / electrolyte was responsible for relatively hampered photovoltaic performance at peak absorption.

DOI： 10.1117/1.JPE.10.045501

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Boosting the Efficiency of Low-Cost T-C-O-Less Dye-Sensitized Solar Cells Employing Nanoparticle Spacers and Cobalt Complex Redox Shuttle 査読有り

Molla M.Z., Baranwal A.K., Hayase S., Pandey S.S.

ACS Applied Electronic Materials   2 ( 9 )   2721 - 2729   2020年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020 American Chemical Society. A strategy has been explored to enhance the diffusion of Co2+/3+ species through the dye-stained nanoparticle spacer employed as an electrolyte absorbing layer with different nanoparticle sizes of TiO2 (30 and 20 nm) and ZrO2 (15 nm) films in transparent conducting oxide-less back-contact dye-sensitized solar cells (T-C-O-less B-C-DSCs). A dye-stained nanoparticle spacer with a relatively larger particle of the TiO2 (30 nm) film brought about easy diffusion of cobalt(II/III) complexes leading to an enhanced photoconversion efficiency (PCE) of 6.55% as compared to relatively smaller nanoparticle of the TiO2 (20 nm) film (4.95%) and ZrO2 (15 nm) film (2.03%). The T-C-O-less B-C-DSC exhibits a lower PCE of 6.55% relative to the T-C-O-based DSC (9.10%) owing to relatively hampered diffusivity of [Co(bpy)3]3+/2+ complexes through perforated holes of the SS-mesh as well as the nanoparticle spacer. A differential study reveals that the cobalt electrolyte exhibits much improved light accumulation in the range 330-430 nm relative to the iodine electrolyte counterpart. The corrosion study of the SS-mesh and Ti-protected SS-mesh reveals that stable T-C-O-less B-C-DSCs can be attained only by the cobalt electrolyte because of its mild nature toward the SS-mesh and Ti metal as compared to the iodine electrolyte.

DOI： 10.1021/acsaelm.0c00437

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Parametric optimization of back-contact T-C-O-free dye-sensitized solar cells employing indoline and porphyrin sensitizer based on cobalt redox electrolyte 査読有り

Molla M.Z., Baranwal A.K., Kapil G., Hayase S., Pandey S.S.

Solar Energy   208   411 - 418   2020年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020 International Solar Energy Society Transparent-conductive-oxide-free (T-C-O-free) back-contact (B-C) dye-sensitized solar cell (DSC) utilizing flexible Stainless Steel (SS) mesh (SS-mesh) supported with mesoporous TiO2 as a photoanode employing cobalt electrolyte is being presented. A thin layer of Ti metal over the SS-mesh was ascertained to be essential to retard the back electron reaction, which was confirmed by the dark current measurements. The interfacial contact between the SS-mesh and nanoporous (NP) TiO2 of the photoanode of T-C-O-free B-C-DSC was driven to influence the photovoltaic performance greatly. It was confirmed by electrochemical impedance analysis that NP TiO2 of 30 nm exhibited less charge transfer impedance observed at TiO2-dye-electrolyte interface as compared to TiO2 of having particle size of 15–20 nm. T-C-O-free B-C-DSC employing dye mixer combination of indoline dyes D-131 and D-205 (1:1) with relatively larger NP of TiO2 (30 nm) as compared to TiO2 of 15–20 nm exhibited enhanced photoconversion efficiency (PCE) of 4.02%. To increase the PCE even further, T-C-O-free B-C-DSC with cobalt based electrolyte sensitized with porphyrin (YD2-o-C8)-dye bearing a larger optical window was investigated. An optimized 10 µm thickness of the TiO2 layer was found to be optimum leading to an enhanced PCE of 5.26%.

DOI： 10.1016/j.solener.2020.08.011

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Stability Improvement of Perovskite Solar Cells by Adding Sb-Xanthate to Precursor Solution 査読有り

Nam K.S., Krishnamurthy S., Qing S., Toyoda T., Yoshino K., Minemoto T., Ma T., Pandey S., Hayase S.

Physica Status Solidi (A) Applications and Materials Science   217 ( 18 )   2020年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020 Wiley-VCH GmbH Herein, it is reported that the stability of a halogenated perovskite (PVK) solar cell consisting of an fluorine-doped tin oxide (FTO) substrate/TiO2/CH3NH3PbI3/N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi[9H-fluorene]-2,2′,7,7′-tetramine/Ag/Au structure is improved by adding Sb-xanthate to the PVK layer without large loss of efficiency. The Sb-element-rich layer is observed on top of the PVK layer. From the X-ray photoelectron spectroscopy (XPS) study, it is concluded that an inorganic SbxOy passivation layer on the PVK layer is prepared by baking the solution of the Sb-xanthate and the PVK precursor. The inorganic layer prevents moisture and oxygen from penetrating into the PVK layer. This article provides a new method to obtain a passivation layer on a PVK layer by baking a mixture solution in one step for improving solar cell stability.

DOI： 10.1002/pssa.202000144

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Reduced contact resistance in organic field-effect transistors fabricated using floating film transfer method 査読有り

Bhargava K., Yadav N., Kumari N., Pandey S.S., Singh V.

Journal of Materials Science: Materials in Electronics   31 ( 18 )   15277 - 15285   2020年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. This paper presents an in-depth performance-based comparison of organic field-effect transistors (OFETs) prepared using the conventional spin coating (SC) technique and a recently developed floating film transfer method (FTM). A remarkable improvement in the performance of transistors fabricated using FTM was achieved in comparison to their SC counterparts. The estimated value of width-normalized contact resistance in FTM-based OFETs was an order lower in comparison to that of transistors prepared using SC technique. The observed results were credited to a significant enhancement in the length of π-conjugation due to the presence of edge-on oriented polymer chains of active layer deposited using FTM, leading to the lowering of carrier injection barrier at the Au/P3HT interface. These results were well supported through absorption, photoluminescence and Raman measurements as well as the anisotropy measurements using polarized absorption spectra, which also pointed towards the improvement in the polymer chain alignment of thin films prepared by FTM over that prepared by the conventional SC technique. The results indicate thin film morphology as a key towards reducing the contact resistance in OFETs.

DOI： 10.1007/s10854-020-04092-1

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Orientation of Semiconducting Polymers via Swift Printing and Drawing Techniques for High Performance Organic Electronic Devices 査読有り

Kumari N., Sharma S., Nagamatsu S., Pandey S.S.

Proceedings of AM-FPD 2020 - 27th International Workshop on Active-Matrix Flatpanel Displays and Devices: TFT Technologies and FPD Materials   67 - 70   2020年09月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2020 FTFMD. Recent developments in the field of organic electronics are being triggered by various approaches aiming towards enhancing the charge transport in thin-films of processable organic semiconductors such as novel molecular design, synthesis and increasing their crystallinity and molecular orientation adopting various thin film fabrication techniques. However, intriguing challenges associated with serious health and environment hazards due to inevitable use of halogenated solvents are needed to be addressed amicably before the practical realization of organic electronic devices. In order to address this issue, thin film fabrication techniques like floating-film transfer and friction transfer have been utilized to demonstrate environment friendly and sustainable fabrication of large area thin-films possessing adequate uniformity without comprising the facile charge transport. Organic field effect transistors were fabricated using different regions of the large-area thin films (≥ 10 cm2) and by optimizing casting conditions, uniformity in the field effect mobility (μ) was demonstrated. Besides this, as compared to most commonly used spin coating, one order of magnitude enhancement in the μ was successfully achieved utilizing oriented thin films fabricated by our methods.

DOI： 10.23919/AM-FPD49417.2020.9224472

Kyutacar

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Comparative analysis of metal diffusion effects in polymer films coated with spin coating and floating film transfer techniques 査読有り

Yadav N., Bhargava K., Kumari N., Pandey S.S., Singh V.

Synthetic Metals   264   2020年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020 Elsevier B.V. In this work a comparative analysis between the extent of gold diffusion of the top coated gold layer into the conducting polymer matrix of spin coated polymer films and polymer films coated via floating film transfer method (FTM) has been investigated. For the sake of comparison two different device configurations i.e. ITO/rr-P3HT (spin coated)/Au and ITO/rr-P3HT (spin coated)/rr-P3HT (FTM coated)/Au have been compared. The J-V characteristics of these devices revealed a non-Ohmic injection occurring near the top gold electrode/polymer interface. Furthermore, the current flowing through the device consisting of FTM layer/Au interface was observed to be lower as compared to the one consisting of spin coated layer/Au interface, indicating higher gold diffusion in well-ordered FTM thin films. These observations have been validated by optical and structural characterization methods viz. absorption, photoluminescence, Raman spectroscopy and X-Ray Diffraction (XRD) measurement. Finally Fowler-Nordheim (FN) tunneling currents were studied under high electric field applications for the two devices which confirmed presence of higher barrier at the interface of gold and FTM coated polymer film.

DOI： 10.1016/j.synthmet.2020.116378

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Synthesis, Photophysical characterization and dye adsorption behavior in unsymmetrical squaraine dyes with varying anchoring groups 査読有り

Ajendra Kumar Vats, Anusha Pradhan, Shuzi, Hayase, Shyam S. Pandey

Journal of Photochemistry and Photobiology A: Chemistry ( Elsevier )   394   112467(1) - 112467(12)   2020年03月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Four newly designed unsymmetrical squaraine dyes bearing different functional groups for their anchoring on the surface of mesoporous TiO2 were successfully synthesized aiming towards development of far-red sensitizers for dye-sensitized solar cells (DSSCs). The synthesized dyes were characterized by 1H NMR, fast ion bombardment mass, and subjected to photophysical investigations by electronic absorption/fluorescence emission spectroscopy and cyclic voltammetry. These dyes exhibited excellent solubility in a number of common organic solvents. Adsorption behavior of these dyes on the thin films of mesoporous TiO2 was investigated in detail and results indicated that rate of dye adsorption follows the order −COOH>-PO3H2>OH > SO3H. At the same time, dye desorption studies demonstrated that stability of adsorbed dyes on the mesoporous TiO2 follows the order -PO3H2>>OH>−COOH > –SO3H. Further, implication of the nature of anchoring groups of dye molecules upon the energy levels of their highest occupied molecular orbital and lowest unoccupied molecular orbital was evaluated by both of the combined theoretical and experimental approaches. In spite of enhanced dye loading, very high binding strength and favorable energetic cascade, SQ-143 bearing Phosphonic acid exhibited hampered photovoltaic performance as compared to that of SQ-138 with carboxylic acid anchoring group. Amongst various sensitizers used for present investigation, SQ-138 exhibited best photovoltaic performance having short-circuit current density, open circuit voltage and fill factor of 12.49 mA/cm2, 0.60 V, and 0.53, respectively, leading to power conversion efficiency of 4.07 % after simulated solar irradiation.

DOI： 10.1016/j.jphotochem.2020.112467

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その他リンク： https://www.sciencedirect.com/science/article/pii/S1010603020302665

Molecular Orientation and Anisotropic Charge Transport in the Large Area Thin Films of Regioregular Poly (3-alkylthiopnes) Fabricated by Ribbon-Shaped FTM 査読有り

Atul SM Tripathi, Rakesh Kumar Gupta, Shubham Sharma, Shuichi Nagamatsu, Shyam S Pandey

Organic Electronics ( Elsevier )   81   105683(1) - 105683(9)   2020年03月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Introduction of alkyl chains is a plausible approach to impart the facile solution processability in regioregular (poly-3-alkylthiophenes) (RR-P3ATS) but drastic fall in the conductivity as a function of increasing alkyl chain length restricted the versatile use of its hexyl substituted derivative (P3HT). In this work, fabrication of large area oriented thin films of RR-P3ATs with varying alkyl chain lengths was successfully demonstrated using ribbon shaped floating film transfer method (FTM). Observed decrease in the molecular orientation with increasing alkyl chain length was explained by enhanced alkyl chain inter-digitation as evidenced by trends of d-spacing estimated from the out-of-plane XRD results. In-plane GIXD revealed edge-on orientation in the thin films of all of the P3ATs prepared by ribbon-shaped FTM, which is highly desired for planer charge carrier transport. Parallel oriented thin film of longest alkyl chain (octadecyl) substituted P3AT poly (3-octadecylthiophene) exhibited a field effect transistor (FET) mobility of 1.9 × 10−2 cm2/V, which is about 4–5 orders of magnitude higher as compared its previously reported values estimated by time-of-flight and FET methods. Thus, fabrication of thin films by FTM leads to versatile choice of RR-P3ATs for solution processing for FETs using common organic solvents without having any detrimental impact of alkyl chain length on the charge carrier mobility.

DOI： 10.1016/j.orgel.2020.105687

その他リンク： https://www.sciencedirect.com/science/article/pii/S1566119920300732

Investigation and control of charge transport anisotropy in highly oriented friction transferred polythiophene thin films 査読有り

Nikita Kumari, Manish Pandey, Shuichi Nagamatsu, Masakazu Nakamura, Shyam Sudhir Pandey

ACS Applied Materials & Interfaces ( American Chemical Society )   12 ( 10 )   11876 - 11883   2020年02月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Highly oriented thin films of poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT) were prepared by friction-transfer technique followed by their characterization using polarized absorption spectroscopy, angle-dependent polarized Raman spectroscopy, and X-ray diffraction (XRD) techniques. Orientation in high-molecular-weight (MW) polymers is hampered by chain folding or entanglements, which limit their macromolecular orientation. Interestingly, utilizing high-molecular-weight PBTTT (MW > 50 kDa) and friction-transfer technique, successful fabrication of highly oriented thin films with very high dichroic ratio (∼30) was demonstrated. The role of the substrate’s surface energy and its impact on the field-effect mobility (μ) of the oriented thin films were comprehensively investigated. The influence of annealing the thin films as prepared on the bare and self-assembled monolayer (SAM)-treated SiO2 surfaces exhibiting differential trends of μ was systematically investigated. This was explained by partial and complete conformational transformation of macromolecules on bare and SAM-treated SiO2 surfaces, respectively, after annealing them beyond liquid crystalline phase transition temperature, as revealed by in-plane and out-of-plane XRD results. On bare SiO2, optimum μ up to 0.03 cm2 V–1 s–1 along the backbone orientation was obtained for the thin films annealed to 120 °C; whereas, it reached up to 0.36 cm2 V–1 s–1 on SAM-treated SiO2 after annealing at 200 °C. Finally, a charge transport mechanism was proposed taking evidence from the anisotropic optical and electrical characteristics of the friction-transferred PBTTT films into consideration.

DOI： 10.1021/acsami.9b23345

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2D positional mapping of casting condition driven microstructural distribution in organic thin films 査読有り

Kumari N., Pandey M., Nagamatsu S., Pandey S.S.

Japanese Journal of Applied Physics   59 ( SC )   2020年02月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2019 The Japan Society of Applied Physics. Fabrication of large-area thin films and their swift characterization is highly desired for the commercial aspects of the organic electronic devices. Although a number of techniques have been proposed for the large-area thin film fabrication, the microstructural variation is still an issue. In this work, the facile characterization of distribution in thickness and macromolecular ordering in the drop-casted and spin-coated poly(3-hexylthiophene) thin films have been performed through newly developed 2D positional mapping technique. Through this technique, a comparative analysis of the absorption spectra in terms of peak absorbance and excitonic bandwidth (W) was performed for the whole sample, the lower value of W observed for the drop-casted thin film depicts its molecular ordering. Moreover, the difference in W (≈ 10 meV) was noticed between two points (≈1 mm apart) on the drop-casted film, which corresponds to the difference in microstructural ordering and it is complicated to characterize through the conventional spectroscopic techniques.

DOI： 10.7567/1347-4065/ab48b9

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2D positional mapping of casting condition driven microstructural distribution in organic thin films 査読有り

Nikita Kumari, Manish Pandey, Shuichi Nagamatsu, Shyam S Pandey

Japanese Journal of Applied Physics ( IOP Science )   69 ( SC )   SCCA06-1 - SCCA06-6   2019年11月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Fabrication of large-area thin films and their swift characterization is highly desired for the commercial aspects of the organic electronic devices. Although a number of techniques have been proposed for the large-area thin film fabrication, the microstructural variation is still an issue. In this work, the facile characterization of distribution in thickness and macromolecular ordering in the drop-casted and spin-coated poly(3-hexylthiophene) thin films have been performed through newly developed 2D positional mapping technique. Through this technique, a comparative analysis of the absorption spectra in terms of peak absorbance and excitonic bandwidth (W) was performed for the whole sample, the lower value of W observed for the drop-casted thin film depicts its molecular ordering. Moreover, the difference in W (≈ 10 meV) was noticed between two points (≈1 mm apart) on the drop-casted film, which corresponds to the difference in microstructural ordering and it is complicated to characterize through the conventional spectroscopic techniques.

Kyutacar

その他リンク： https://iopscience.iop.org/article/10.7567/1347-4065/ab48b9/meta

P3HT Nanofibrils Thin-Film Transistors by Adsorbing Deposition in Suspension 査読有り

Shuichi Nagamatsu, Masataka Ishida, Shougo Miyajima, Shyam S Pandey

Materials ( MDPI )   12 ( 21 )   3643   2019年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A novel film preparation method utilizing polymer suspension, entitled adsorbing deposition in suspensions (ADS), has been proposed. The poly(3-hexylthiophene) (P3HT) toluene solution forms P3HT nanofibrils dispersed suspension by aging. P3HT nanofibrils are highly crystallized with sharp vibronic absorption spectra. By the ADS method, only P3HT nanofibrils in suspension can be deposited on the substrate surface without any disordered fraction from the dissolved P3HT in suspension. Formed ADS film contains only the nanostructured conjugated polymer. Fabricated polymer thin-film transistor (TFT) utilizing ADS P3HT film shows good TFT performances with low off current, narrow subthreshold swing and large on/off current ratio

DOI： 10.3390/ma12213643

その他リンク： https://www.mdpi.com/1996-1944/12/21/3643

Clitoria ternatea flower as natural dyes for Dye-sensitized solar cells 査読有り

Azwar Hayat, A Erwin E Putra, Novriany Amaliyah, Shyam S Pandey

IOP Conference Series: Materials Science and Engineering ( IOP Science )   619 ( 1 )   012049-1 - 012049-6   2019年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Clitoria ternatea flowers have been investigated as a natural sensitizer in Dye-sensitized solar cell (DSSC). Dried C. ternatea flowers ware immersed in ethanol for 48 hours in dark room to obtain anthocyanin pigments. We compared the photovoltaic performance of the sensitizers with Titanium dioxide (TiO2) only and TiO2 with scattering layers. C. ternatea dyes have higher Power Conversion Efficiency (PCE) when applied in TiO2 with scattering layers compared to standard TiO2 semiconductors. Scattering layer (SL) has increased the light path inside the photo-anode film that doubled the short-circuit current (Jsc) and enhanced the open circuit voltage (Voc) compared to TiO2 based cell without the SL. In conclusion, from the result, higher electron injections can be achieved by light management on photo-anode film with scattering layers as one of strategy to enhance the efficiency for further low cost and environment-friendly solar cell.

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その他リンク： https://iopscience.iop.org/article/10.1088/1757-899X/619/1/012049/meta

Role of device architecture and AlOX interlayer in organic Schottky diodes and their interpretation by analytical modeling 査読有り

Nikita Kumari, Manish Pandey, Kengo Hamada, Daisuke Hirotani, Shuichi Nagamatsu, Shuzi Hayase, Shyam S Pandey

Journal of Applied Physics ( American Institute of Physics )   126   125501-1 - 125501-12   2019年09月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Considering the pivotal role of interfaces in controlling the performance of organic electronic devices, implications of metal/organic interfacial quality in a Schottky barrier diode (SBD) are investigated. The nature of metal/organic interfaces and the thin film quality of regioregular poly (3-hexylthiophene) based SBDs fabricated in different device architectures are investigated using experimental and theoretical modeling. The importance of oxidized aluminum nanostructures as an interlayer at the Schottky interface for the dramatic enhancement of the rectification ratio (>106 at ±5 V) has been demonstrated, which is attributed to suppressed leakage current due to the oxide layer and the formation of a charge double layer. Furthermore, electrical performances of all the SBDs were modeled in terms of an underlying particular phenomenon solely or with the combination of multiple physical phenomena. The combined modeling equation used in this work fits well for the different device architectures, which validates its generality in order to extract the device parameters

DOI： 10.1063/1.5109083

その他リンク： https://aip.scitation.org/doi/full/10.1063/1.5109083

Recent advances in the orientation of conjugated polymers for organic field-effect transistors 査読有り

Manish Pandey, Nikita Kumari, Shuichi Nagamatsu, Shyam S Pandey

Journal of Materials Chemistry C, ( Royal Society of Chemistry )   7   13323 - 13351   2019年09月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Solution processable conjugated polymers (CPs) possess unique molecular structures in terms of extended π-conjugation in combination with quasi 1-dimensionality, imparting them with an inherent tendency for molecular self-assembly and ultimately determining their optoelectronic properties. Short-range molecular ordering and long-range macroscopic orientation are two different but interdependent phenomena, which should be optimized depending on the nature of electronic devices (planar versus vertical). Judicious control of the macromolecular orientations and conformation-assisted morphologies of CPs are key for determining and controlling the anisotropic charge transport in organic field effect transistors (OFETs). The present review focuses on different solution-based approaches for thin film fabrication developed in the last two decades aimed towards controlling the film morphologies and macroscopic

DOI： 10.1039/C9TC04397G

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Implication of Molecular Weight on Optical and Charge Transport Anisotropy in PQT-C12 Films Fabricated by Dynamic FTM 査読有り

Atul SM Tripathi, Shifumi Sadakata, Rakesh Kumar Gupta, Shuichi Nagamatsu, Yoshito Ando, Shyam S Pandey

ACS Applied Materials and Interfaces ( The American Chemical Society )   11 ( 31 )   28088 - 28095   2019年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Large area (>20 cm × 2 cm)-oriented thin films of PQT-C12 with varying molecular weight and polydispersity index (PDI) were fabricated by the ribbon-shaped floating film transfer method aiming toward their application as an active semiconductor element of organic field effect transistors (OFETs). Investigation on the influence of the molecular weight and PDI upon the extent of molecular alignment and anisotropic charge transport was systematically carried out. It has been demonstrated that high molecular weight in combination with low PDI not only leads to a very high optical anisotropy >10 but also high charge carrier anisotropy with a hole mobility of about 0.07 cm2/V·s for OFETs using parallel-oriented PQT-C12 thin films. Such a structure–property correlation is highly beneficial for the development of high performance organic electronic devices by synergistic and amicable tuning of the optoelectronic anisotropies and polymer synthetic variables.

Kyutacar

その他リンク： https://doi.org/10.1021/acsami.9b06568

Wide wavelength photon harvesting in dye-sensitized solar cells utilizing cobalt complex redox electrolyte: Implication of surface passivation 査読有り

Anusha Pradhan, Maryala Saikiran, Gaurav Kapil ,Shuzi Hayase, Shyam S. Pandey

Solar Energy Materials and Solar Cells ( Elsevier )   195   122 - 133   2019年03月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

A combination of near infra-red (NIR) photon harvesting and cobalt electrolytes having deeper redox energy level are needed for the fabrication of high efficiency dye-sensitized solar cells (DSSCs). A logical molecular design of unsymmetrical squaraine dye (SQ-110) as a representative of NIR dyes has been demonstrated to function well in DSSC using cobalt complex redox electrolyte. Problem of mass transport limitations due to the bulky cobalt complex ions leading to relatively enhanced charge recombination was amicably solved by single as well as multiple compact metal oxide surface passivation on both of the transparent conducting oxide substrate as well as mesoporous TiO2. Complete absence of light absorption beyond 550 nm wavelength region by D-35 and utilization of a complementary light harvesting dye SQ-110 led to efficient wide wavelength photon harvesting. DSSC fabricated using a dye cocktail of D-35 and SQ-110 in 4:1 ratio resulted in to photoconversion efficiency (PCE) of 7.2%, which is much higher as compared to the constituent individual sensitizers D-35 (3.6%) and SQ-110 (1.9%). This synergistic enhancement in PCE by dye cocktail was associated with the mutual co-operation of respective dyes in terms controlling the dye aggregation and complementary photon harvesting. In this dye cocktail system, D-35 is involved in the prevention of dye aggregation, lower wavelength photon harvesting and energy transfer induced photocurrent enhancement.



DOI： 10.1016/j.solmat.2019.03.013

Kyutacar

Optoelectrical anisotropy in graphene oxide supported polythiophene thin films fabricated by floating film transfer 査読有り

Rajiv K Pandey, Atul SM Tripathi, Shyam S Pandey, Rajiv Prakash

Carbon ( Elsevier )   147   252 - 261   2019年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A facile method for the fabrication of highly oriented hybrid thin films of conjugated polymer (CP) with graphene oxide (GO) as 2D nano-filler over the high surface tension liquid substrate by floating film transfer is being reported. Formation of the self-assembled oriented hybrid thin film has been validated using multiple characterization techniques. Hybrid thin films thus prepared have been used for the fabrication of organic field effect transistors (OFETs) followed by investigation of anisotropic charge carrier transport. OFETs made with hybrid films oriented in channel direction exhibited the superior device performance with >6 fold augmentation in field effect mobility (μ) and one order improvement in on/off ratio as compared to that of devices based on pristine CP. However, pristine polymer shows 2.2 fold enhancement in mobility and one order augmentation in on/off ratio in parallel orientation as compared to the corresponding perpendicularly oriented films. Thus, our study has elucidated a path to obtain oriented, aligned, and self - assembled hybrid films for further improvement in the device performance aiming towards the applications in organic electronics.

DOI： 10.1016/j.carbon.2019.02.086

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S0008622319302179

Passivation of Grain Boundary by Squaraine Zwitterions for Defect Passivation and Efficient Perovskite Solar Cells 査読有り

Zhen Wang, Anusha Pradhan, Muhammad Akmal kamarudin, Manish Pandey, Shyam S Pandey, Putao Zhang, Chi huey Ng, Atul SM Tripathi, Tingli Ma, Shuzi Hayase

ACS Applied Materials and Interfaces ( The American Chemical Society )   11 ( 10 )   10012 - 10020   2019年02月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Unavoidable defects in grain boundaries (GBs) are detrimental and critically influence the organometal halide perovskite performance and stability. To address this issue, semiconducting molecules have been employed to passivate traps along perovskite GBs. Here, we designed and synthesized three squaraine molecules (SQ) with zwitterionic structure to interact with under-coordinated Pb2+ and passivate Pb–I antisite defects. Density functional theory calculation shows symmetric O atoms could coordinate with perovskite grains simultaneously, resulting in continuous charge distribution at the SQ–perovskite interface. The energetic traps distribution in CH3NH3PbI3 perovskite is influenced significantly by the interaction between SQ and perovskite as analyzed by thermally stimulated current, in which the deep-level defects are considerably reduced due to efficient SQ passivation. In addition, we explore how SQ …

DOI： 10.1021/acsami.8b22044

その他リンク： https://pubs.acs.org/doi/abs/10.1021/acsami.8b22044

2D positional profiling of orientation and thickness uniformity in the semiconducting polymers thin films 査読有り

Nikita Kumari, Atul SM Tripathi, Shifumi Sadakata, Manish Pandey, Shuichi Nagamatsu, Shuzi Hayase, Shyam S Pandey

Organic Electronics ( Elsevier )   68   221 - 229   2019年02月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Harnessing the full potential of solution processable conjugated polymers (CPs) as active semiconductor elements lies in the facile thin film fabrication along with amicable control of molecular self-assembly and orientation. Probing the nature and uniformity of thin films are inevitable for fabrication of devices with high reproducibility. Herein, a new method for the fast and facile profiling of thickness and molecular orientation of large area thin films is being reported. Thin films of PBTTT-C14 fabricated by three different methods like floating film transfer method (FTM), friction transfer and spin coating were subjected to profiling of thickness and molecular orientation using 2D positional mapping system followed by fabrication of organic thin film transistors. In order to prove applicability of the mapping system on other CPs, oriented films of PQT-C12 were also prepared by FTM and optical anisotropy estimated by the mapping system (23.0) and conventional spectrophotometer (22.4) validates the performance of our positional mapping system. Spin-coated thin films of PBTTT-C14 subjected to positional profiling of the film uniformity revealed that films are non-uniform and there was a gradual increase in the thickness from center to the periphery.

DOI： 10.1016/j.orgel.2019.02.011

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S1566119919300746

Back-illuminated dye-sensitized solar cell flexible photoanode on titanium foil 査読有り

Shaban S., Shafie S., Pandey S.S., Lokman M.Q., Ahmad F., Hamidon M.N., Sharif N.F.M.

ASM Science Journal   12 ( SpecialIssue4 )   29 - 35   2019年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2019, Akademi Sains Malaysia. This paper reports the preparation and performance analysis on dye-sensitized solar cells (DSSC) using titanium (Ti) foil as flexible photoanode for back-illuminated measurement. Performance differences were also carried with the fluorine-doped tin oxide (FTO) glass photoanode using the back and front-illuminated technique. The hydrogen peroxide (H2O2) treated Ti foil surface was applied and the doctor blade method was used for deposition on photoanode during the process of fabrication. Surface morphology of the treated Ti Foil with H2O2 shows the formation of TiO2 nanostructure which results in significant attachment of TiO2 layer on Ti Foil. The results on measurement show that the fabricated flexible photoanode DSSC has an efficiency of power conversion at 1.00% under 1.5 A. M solar radiation by using back-illuminated while DSSC with solid-state glass photoanode has an efficiency power conversion at 0.53% (back-illuminated) and 2.22% (front-illuminated). However, the flexible photoanode DSSC has better power conversion efficiency than the solid-state glass photoanode DSSC under the condition of back-illumination. It is lower in result comparatively with front illumination DSSC due to the coated of platinum at the counter electrode that reflects light partially, while electrolyte iodine absorbs some photons and effects on DSSC performance.

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85084484893&origin=inward

Synthesis, characterizations and photo-physical properties of novel lanthanum (III) complexes 査読有り

Iffat Ameen, Abhishek Kumar Tripathi, Afshan Siddiqui, Gaurav Kapil, Shyam S Pandey, Umesh Nath Tripathi

Journal of Taibah University for Science   12 ( 6 )   796 - 808   2018年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A series of novel complexes of La(III) with substituted pyrazolines and mixed ligand complexes with these pyrazolines and thio-ligands have been synthesized and characterized by elemental analysis, molecular weight measurement, Fourier transform infra-red, 1H and 13C NMR spectroscopy. The particle/crystallite sizes were confirmed by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopic techniques. Optical characterizations have been performed by electronic absorption and fluorescence emission spectroscopies in order to investigate their luminescence behaviour, which reveals fairly good quantum yield and fluorescence life time for some of the complexes. Thermal analyses such as thermogravimetric and differential thermal analysis indicate that these complexes are thermally stable at high temperature. Investigations pertaining to solid-state optical absorption spectra and photoelectron yield spectroscopy reveal that upon thermal annealing beyond 300°C, these compounds form dark-brown to black semiconducting materials with an optical band gap between 1.9 and 2.3 eV.

DOI： 10.1080/16583655.2018.1516028

その他リンク： https://www.tandfonline.com/doi/abs/10.1080/16583655.2018.1516028

Facile fabrication of large area oriented conjugated polymer films by ribbon-shaped FTM and its implication on anisotropic charge transport 査読有り

Atul S.M.Tripathi, Nikita Kumari, Shuichi Nagamatsu, Shuzi Hayase, Shyam S.Pandey

Organic Electronics ( Elsevier )   65   1 - 7   2018年10月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Facile fabrication of large area [20 cm (L) × 2 cm (W)] uniform and oriented thin films of a variety of conjugated polymers (CPs) with minimal material wastage has been successfully demonstrated using our newly developed ribbon-shaped floating film transfer method (FTM). Under identical film fabrication conditions of FTM like hydrophilic liquid substrate consisted of ethylene glycol and glycerol (3:1), the temperature of 60 °C and polymer concentration 1% (w/w) in chloroform, order of molecular orientation was found to be PQT-C12 > F8T2 > NR-P3HT > PBTTT-C14 > PTB7. Depending on the nature of polymeric backbone, CPs exhibited different optical anisotropies in their oriented thin films, which was explained in terms of nature and rigidity of polymeric chains in the light of persistent length. Organic field effect transistors fabricated using these CPs exhibited clear p-type behaviour and anisotropic charge transport. Amongst various CPs used, PQT-C12 not only exhibited the highest optical anisotropy (DR = 5.1) but also highest anisotropic charge transport (μ||/μ⊥ = 7.1). Ribbon-shaped thin films of PQT-C12 prepared by slider based FTM exhibited best device performance with charge carrier mobility of 5.0 × 10−2 cm2/V and ON/OFF ratio of 106, when films were oriented parallel to the channel direction. Interestingly, a mobility of parallel oriented thin films prepared by FTM was about two orders of magnitude higher compared to the OFETs fabricated using conventional spin coating (6.7× 10−4 cm2/V).

DOI： 10.1016/j.orgel.2018.10.043

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S1566119918305585

Synthesis and Optoelectrical Characterization of Novel Squaraine Dyes Derived from Benzothiophene and Benzofuran 査読有り

G. Hanumantha Rao, Manish Pandey, Kamatham Narayanaswamy, Ravulakollu Srinivasa Rao, Shyam S. Pandey, Shuzi Hayase, and Surya Prakash Singh

ACS Omega   3 ( 10 )   13919 - 13927   2018年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Synthesis and photophysical characterizations of two novel small molecules SQ-BEN-THI and SQ-BEN-FUR with D–A–D molecular structure consisting of squaraine as central unit and benzothiophene and benzofuran as end groups are being reported. Apart from very sharp and intense light absorption by these molecular sensitizers in near-infrared (NIR) wavelength region, their possibility as small molecular organic semiconductor was also explored after fabricating organic field-effect transistors (OFETs). Results obtained from photophysical, electrochemical, and quantum chemical studies were combined to elucidate the structural and optoelectronic properties. Electrical characterization pertaining to the charge-transport properties carried after OFET fabrication exhibited field-effect mobilities of 4.0 × 10–5 and 5.4 × 10–5 cm2/(V s) for SQ-BEN-THI and SQ-BEN-FUR, respectively. After thermal annealing at 130 °C, the field-effect mobility was found to increase for both squaraine dyes. Relatively facile carrier transport in SQ-BEN-FUR compared to that of SQ-BEN-THI could be attributed to relatively higher backbone planarity as indicated from optimized molecular structure obtained after density functional theory calculations. This work may guide for further molecular design and synthesis of novel squaraine dyes for high-performance OFET applications.

DOI： 10.1021/acsomega.8b01240

Kyutacar

Enhancement of charge transport in quantum dots solar cells by N-butylamine-assisted sulfur-crosslinking of PbS quantum dots 査読有り

Zhen Wang, Zhaosheng Hu, Muhammad Akmal Kamarudin, Gaurav Kapil, Atul Tripathi, Qing Shen, Kenji Yoshino, Takashi Minemoto, Sham S. Pandey, Shuzi Hayase

Solar Energy   174   399 - 408   2018年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A novel and facile strategy to realize selective inorganic ligand (S2−) exchange on Pb-rich surface of PbS colloidal quantum dots (QDs) has been demonstrated. This was achieved via xanthate ligand decomposition at room temperature without damaging the QDs surface. This proposed method offers an amicable solution for the limitation that inorganic-terminated colloidal QDs are restricted by the specific requirement to solvents with high dielectric constant. Furthermore, Introduction of S2− to form sulfur-crosslinking PbS QDs enables reaction force-induced QDs arrays and smooth surface morphology of the spin-coated QDs film as evidenced by atomic force microscopy. Passivation of QDs by bromide combined with sulfur led to stronger electronic coupling between adjacent QDs as compared to bromide-only passivated QDs counterparts. Bromide and sulfur hybrid-capped QDs exhibited remarkably enhanced carrier mobility from 1.66 × 10−4 cm2/V s to 5.0 × 10−1 cm2/V s as evidenced by the Hall- Effect measurement. The smooth QDs film morphology and higher charge transport contributed to the boost in the power conversion efficiency of QDs solar cells up 4.96% compared that using only CTAB passivated PbS QDs solar cells (3.04%). This controlled sulfurization approach paves a potential way for improved optoelectronic properties and devices based on QDs.

DOI： 10.1016/j.solener.2018.09.026

その他リンク： https://www.sciencedirect.com/science/article/pii/S0038092X18308983

Synthesis and Photophysical Characterization of Unsymmetrical Squaraine Dyes for Dye-Sensitized Solar Cells utilizing Cobalt Electrolytes 査読有り

Anusha Pradhan, Maryala Saikiran, Gaurav Kapil, Shuzi Hayase, and Shyam Sudhir Pandey

ACS Applied Energy Materials   1 ( 9 )   4545 - 4553   2018年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Development of novel near-infrared (near-IR) dyes compatible with cobalt complex based redox shuttles for their utilization as sensitizer is inevitable for the fabrication of high-efficiency dye-sensitized solar cells (DSSCs). A series of newly designed unsymmetrical squaraine dyes as a model of near-IR sensitizer were synthesized and characterized for their application as far-red sensitizers of DSSCs utilizing Co(bpy)2+/3+ redox electrolyte. It was shown that logical molecular design led to not only energetic tunability of the sensitizers but also the possibility of good far-red photon harvesting up to 750 nm. One of the newly designed sensitizers, SQ-110, bearing two long alkyl substituents in combination with an electron donating methoxy group directly linked to the aromatic ring was par excellent in terms of its photoconversion efficiency among the dyes utilized in this work. DSSC fabricated using SQ-110 as sensitizer and Co(bpy)2+/3+ redox electrolyte furnished a photoconversion efficiency of 1.98% along with good photon harvesting mainly in the far-red wavelength region. It was further demonstrated that dye molecular structure plays a rather more prominent role than their energetics in controlling the overall device performance of the DSSCs.

DOI： 10.1021/acsaem.8b00653

Kyutacar

A review of transparent solar photovoltaic technologies 査読有り

Alaa AF Husain, Wan Zuha W Hasan, Suhaidi Shafie, Mohd N Hamidon, Shyam Sudhir Pandey

Renewable and Sustainable Energy Reviews   94   779 - 791   2018年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.rser.2018.06.031

Kyutacar

Study Pertaining to Observe the Effect of PbI2 Passivation on Carbon Electrode for Perovskite Solar Cells by Quartz Crystal Microbalance System 査読有り

Putao Zhang, Gaurav Kapil, Kengo Hamada, Shyam Sudhir Pandey, Tingli Ma, Shuzi Hayase

ACS Sustainable Chemistry & Engineering   6 ( 8 )   10221 - 10228   2018年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acssuschemeng.8b01550

Anisotropic charge transport in highly oriented films of semiconducting polymer prepared by ribbon-shaped floating film 査読有り

Atul SM Tripathi, Manish Pandey, Shifumi Sadakata, Shuichi Nagamatsu, Wataru Takashima, Shuzi Hayase, Shyam S Pandey

Applied Physics Letters 112 (12), 123301 (2018).   112 ( 12 )   123301-1 - 123301-5   2018年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1063/1.5000566

Kyutacar

その他リンク： https://aip.scitation.org/

Implications of doping and depletion on the switching characteristics in polymer-based organic field-effect transistors 査読有り

Shashi Tiwari, Manish Pandey, Wataru Takashima, Shuichi Nagamatsu, SK Balasubramanian, Shuzi Hayase, Shyam S Pandey, Rajiv Prakash

Organic Electronics   56   152 - 158   2018年02月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.orgel.2018.02.012

Kyutacar

Rapid Formation and Macroscopic Self-Assembly of Liquid-Crystalline, High-Mobility, Semiconducting Thienothiophene 査読有り

Manish Pandey, Ashwathanarayana Gowda, Shuichi Nagamatsu, Sandeep Kumar, Wataru Takashima, Shuzi Hayase, Shyam S. Pandey

Advanced Materials Interfaces   5 ( 6 )   1700875(1) - 1700875(11)   2018年01月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

A synergistic approach to enhance charge-carrier transport in organic semiconductors along with facile solution processing and high performance is crucial for the advancement of organic electronics. The floating film transfer method (FTM) is used as a facile and cost-effective method for the fabrication of large-scale, uniform, highly oriented poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (pBTTT C-14) films under ambient conditions. Utilization of such oriented films as the active semiconducting layer in organic field-effect transistors (OFETs) results in highly anisotropic charge-carrier transport. Highly oriented, FTM-processed pBTTT C-14 thin films are characterized by polarized electronic absorption and Raman spectroscopy, atomic force microscopy, out-of-plane X-ray diffraction, and grazing incident X-ray diffraction (GIXD) measurements. The GIXD data indicate an edge-on orientation, which is highly desirable for planar devices such as OFETs. OFETs built using the oriented films show a mobility anisotropy of 10 and the highest mobility is 1.24 cm2 V−1 s−1 along the backbone orientation, which is among the highest value reported for this class of materials using a similar device configuration.

DOI： 10.1002/admi.201700875

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その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/admi.201700875/abstract

Casting Control of Floating-films into Ribbon-shape Structure by modified Dynamic FTM 査読有り

Tripathi, M Pandey, S Nagamatsu, SS Pandey, S Hayase, W Takashima

Journal of Physics: Conference Series   924 ( 1 )   012014(1) - 012014(6)   2017年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

We have developed a new method to obtain Ribbon-shaped floating films via dynamic casting of floating-film and transfer method (dynamic-FTM). Dynamic-FTM is a unique method to prepare oriented thin-film of conjugated polymers (CPs) which is quick and easy. This method has several advantages as compared to the other conventional casting procedure to prepare oriented CP films. In the conventional dynamic FTM appearance of large scale circular orientation poses difficulty not only for practical applications but also hinders the detailed analysis of the orientation mechanism. In this present work, pros and cons of this newly proposed ribbon-shaped floating-film have been discussed in detail from those of the conventional floating-film prepared by dynamic-FTM.

DOI： 10.1088/1742-6596/924/1/012014

Kyutacar

その他リンク： http://iopscience.iop.org/article/10.1088/1742-6596/924/1/012014/meta

Photophysical Characterization and BSA Interaction of Direct Ring Carboxy Functionalized Symmetrical squaraine Dyes 査読有り

Maryala Saikiran, Shyam S Pandey, Shuzi Hayase, Tamaki Kato

Journal of Physics: Conference Series   924 ( 1 )   012006(1) - 012006(10)   2017年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A series of far-red sensitive symmetrical squaraine dyes bearing direct–COOH
functionalized indole ring were synthesized, characterized and subjected to photophysical
investigations. These symmetrical squaraine dyes were then subjected to investigate their
interaction with bovine serum albumin (BSA) in Phosphate buffer solutions. All the squaraine
dyes under investigation exhibit intense and sharp optical absorption mainly in the far-red
wavelength region from 550 nm-700 nm having very high molar extinction coefficients from
1.3× 10 5 dm 3. mol− 1. cm− 1. A very small Stokes shift of 10-17 nm indicates the rigid
conformational structure of squaraine chromophore. Interaction of these dyes with BSA
leads to not only enhanced emission intensity but also bathochromically shifted absorption
maximum due to formation of dye-BSA conjugate. These dyes bind strongly with BSA

DOI： 10.1088/1742-6596/924/1/012006

Kyutacar

その他リンク： http://iopscience.iop.org/article/10.1088/1742-6596/924/1/012006/meta

Parametric Optimization of Dye-Sensitized Solar Cells Using Far red Sensitizing Dye with Cobalt Electrolyte 査読有り

A Pradhan, M Saikiran, G Kapil, S S Pandey, S Hayase

Journal of Physics: Conference Series   924   012001(1) - 012001(9)   2017年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A far-red sensitizing dye SQ-75 has been employed as a model sensitizer with Co
(bpy) 2+/3+ redox electrolytes to fabricate dye-sensitized solar cells (DSSCs) and optimize
the various device parameters which influence the overall photoconversion efficiency (PCE).
It has been found that the optimization of the TiO 2 thickness, surface treatment with TiCl 4,
and an optimum amount of the chenodeoxycholic acid (CDCA) as coadsorber are necessary
to attain the overall improved PCE. TiCl 4 surface treatment on both FTO and TiO 2 has been
found to outperform as compared to their untreated counterparts owing to the suppression of
the charge recombination. DSSCs with an optimized TiO 2 thickness of 6 μm and CDCA
concentration of 4 mM have exhibited best performance due to enhanced photon harvesting
and reduced dye aggregation, respectively.

DOI： 10.1088/1742-6596/924/1/012001

Kyutacar

その他リンク： http://iopscience.iop.org/article/10.1088/1742-6596/924/1/012001/meta

Investigation of the minimum driving force for dye regeneration utilizing model squaraine dyes for dye-sensitized solar cells 査読有り

Anusha Pradhan, Takuya Morimoto, Maryala Saikiran, Gaurav Kapil, Shuzi Hayase, Shyam S Pandey

Journal of Materials Chemistry A   5 ( 43 )   22672 - 22682   2017年10月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Combined theoretical and experimental approaches were implemented to design model far-red sensitive unsymmetrical squaraine dyes in order to estimate the minimum energy barrier required for dye regeneration. Our logical molecular design indicated that it is possible to have a fine control on the energetics within 0.2 eV only by the judicious selection of substituents and alkyl chain length keeping the main π-molecular framework the same. The utilization of the LSDA functional under TD-DFT calculations offered an effective and economical computational method for the reliable prediction of the energetics as well as the absorption maximum of the sensitizers. Among the designed dyes under investigation, SQ-75 exhibited the best photovoltaic performance, having a short-circuit current density of 10.92 mA cm−2, open circuit voltage of 0.57 V and a fill factor of 0.67, leading to a photoconversion efficiency of 4.25% despite having photon harvesting mainly in the far-red region. The best photon harvesting by SQ-75, even with an energy difference of only 0.12 eV between the energy of its highest occupied molecular orbital and redox energy level I−/I3− electrolyte, corroborates the possibility for dye regeneration with such a small driving force.

DOI： 10.1039/C7TA06990A

Kyutacar

Efficient near infrared fluorescence detection of elastase enzyme using peptide-bound unsymmetrical squaraine dye 査読有り

Maryala Saikiran, Daisuke Sato, Shyam S Pandey, Shuzi Hayase, Tamaki Kato

Bioorganic & Medicinal Chemistry Letters   27 ( 17 )   4024 - 4029   2017年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.bmcl.2017.07.057

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S0960894X17307643

Air-stable vapor phase sensing of ammonia in sub-threshold regime of poly(2,5-bis(3-tetradecylthiophen-2yl)thieno(3,2-b)thiophene) based polymer thin-film transistor 査読有り

Sahu P., Pandey M., Kumar C., Pandey S., Takashima W., Mishra V., Prakash R.

Sensors and Actuators, B: Chemical   246   243 - 251   2017年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Elsevier B.V. In the present study, device geometry having top contact bottom gated poly(2,5-bis(3-tetradecylthiophen-2yl)thieno(3,2-b)thiophene) (PBTTT) based polymer thin film transistor (PTFT) is reported to measure the changes in electrical responses with the exposure to various concentrations of ammonia vapor at room temperature. PTFT is preferred over other electronic devices due to its multi-parameter characteristics to explore gas sensing capabilities. A facile floating–film transfer method (FTM) is used to prepare an active layer of PTFT by forming optimized thin layer of PBTTT film having a thickness of ∼25 nm. Exposure to various concentrations of ammonia vapor, device parameters like I/O characteristics, mobility, threshold voltage, and trap density are found to change significantly. As PTFT is exposed to 100 ppm ammonia vapor a 70% reduction in mobility is observed whereas threshold voltage shifted to more negative from −17.62 V to −23.64 V. Better sensing capabilities with a detection limit of 0.33 ppm, fast response and recovery of exposed ammonia vapor are observed, when PTFT is operated in sub-threshold regime rather than the cut-off or saturated regime. All the electrical characterizations for the sensing purpose are carried out in ambient but in a closed chamber. Device shows enormous potential for ammonia sensing for real and environmental applications.

DOI： 10.1016/j.snb.2017.02.063

Scopus

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Investigation of Interfacial Charge transfer in Solution Processed Cs2SnI6 Thin Films 査読有り

Gaurav Kapil, Takeshi Ohta, Tsuguo Koyanagi, Yaohong Zhang, Murugan Vigneshwaran, Yuhei Ogomi, Shyam Sudhir Pandey, Kenji Yoshino, Qing Shen, Taro Toyoda, Md Mijanur Rahman, Takashi Minemoto, Takurou N Murakami, Hiroshi Segawa, Shuzi Hayase

Journal of Physical Chemistry C   121 ( 24 )   13092 - 13100   2017年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.jpcc.7b04019

Interplay of Orientation and Blending: Synergistic Enhancement of Field Effect Mobility in Thiophene-Based Conjugated Polymers 査読有り

Manish Pandey, Shuichi Nagamatsu, Wataru Takashima, Shyam Sudhir Pandey, Shuzi Hayase

Journal of Physical Chemistry C   121 ( 21 )   11184 - 11193   2017年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.jpcc.7b03416

Layer-by-layer coating of oriented conjugated polymer films towards anisotropic electronics 査読有り

Pandey M., Sadakata S., Nagamatsu S., Nagamatsu S., Pandey S., Hayase S., Hayase S., Takashima W.

Synthetic Metals   227   29 - 36   2017年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Dynamic casting of floating-film and transferring method for preparing oriented multilayer films of conjugated polymers is reported. This method is based on dynamic casting of a floating-film on liquid substrate to obtain oriented thin-film followed by its transfer on a desired solid substrate. The uniqueness in this method lies in the isolation of casting and coating procedures of oriented films, which enables us to fabricate the oriented multilayer with minimum interlayer interference. It provides a key-technology to build up the organic multi-layered architecture while preserving oriented morphologies. Several types of multilayer films have been prepared and investigated in detail in terms of their film characteristics. The layer-by-layer coating of oriented films demonstrated by this method is found to be a unique feature which overcomes cumbersome procedures in the conventional orientation methods. The coating procedure demonstrated in this study provides a facile methodology to construct anisotropic architectures.

DOI： 10.1016/j.synthmet.2017.02.018

Kyutacar

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Solvent driven performance in thin floating-films of PBTTT for organic field effect transistor: Role of macroscopic orientation 査読有り

Pandey M., Pandey S., Nagamatsu S., Nagamatsu S., Hayase S., Hayase S., Takashima W., Takashima W.

Organic Electronics: physics, materials, applications   43   240 - 246   2017年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Elsevier B.V. Considering the advantages of floating film transfer method (FTM), we have investigated the optical and electronic characteristics of PBTTT-C14 thin-films prepared by the static and the dynamic casting on liquid substrate. It has been demonstrated that judicious selection of solvents during FTM switches the casting mode from the static casting (S-FTM) using high boiling point solvent to the dynamic casting (D-FTM) from low boiling point solvent. Although both of the methods provide the edge-on oriented structure of PBTTT-C14 by XRD, the structural and the optical analyses reveal relatively extended π-conjugation length in parallel D-FTM film as compared to that of S-FTM. A high field-effect mobility (μ) of 0.11 cm 2 /V.s was exhibited by OFETs fabricated by parallel D-FTM film even without any high temperature post-annealing up to the liquid crystalline phase transition. This observed value of μ for parallel D-FTM is 4.7 and 12.8 times higher than the isotropic S-FTM and the perpendicular D-FTM films, respectively.

DOI： 10.1016/j.orgel.2017.01.031

Scopus

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Controlling factors for orientation of conjugated polymer films in dynamic floating-film transfer method 査読有り

Pandey M., Pandey S., Nagamatsu S., Nagamatsu S., Hayase S., Takashima W., Takashima W.

Journal of Nanoscience and Nanotechnology   17 ( 3 )   1915 - 1922   2017年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Copyright © 2017 American Scientific Publishers All rights reserved. Orientation in conjugated polymers is a unique phenomenon by the virtue of their one dimensionality leading to semiconductor performances in organic electronic devices. A unique, cost-effective and highly efficient method for the fabrication of oriented thin film consisted of non-regiocontrolled poly(3-hexylthiophene) (NR-P3HT) using dynamic floating-film transfer method (dynamic-FTM) has been investigated. Orientation of NR-P3HT by dynamic-FTM has been quantitatively measured as the optical anisotropy represented by dichroic ratio (DR). Amongst several factors like concentration of polymer solution, temperature and viscosity of liquid-substrate along with post-annealing temperature, viscosity of liquid-substrate plays a crucial role in controlling the molecular orientation. A judicious control and optimization of various underlying factors affecting the molecular orientation led to relatively high DR of 9.3 even in NR-P3HT films cast by dynamic-FTM.

DOI： 10.1166/jnn.2017.12816

Scopus

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Transparent Conductive Oxide Layer and Hole Selective Layer Free Back-Contacted Hybrid Perovskite Solar Cell 査読有り

Zhaosheng Hu, Gaurav Kapil, Hiromitsu Shimazaki, Shyam Sudhir Pandey, Tingli Ma, Shuzi Hayase

The Journal of Physical Chemistry C   121 ( 8 )   4214 - 4219   2017年02月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.jpcc.7b00760

その他リンク： http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.7b00760

Combined theoretical and experimental approaches for development of squaraine dyes with small energy barrier for electron injection 査読有り

Shyam S Pandey, Takuya Morimoto, Naotaka Fujikawa, Shuzi Hayase

Solar Energy Materials and Solar Cells   159   625 - 632   2017年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.solmat.2015.10.033

Kyutacar

その他リンク： http://www.sciencedirect.com/science/article/pii/S0927024815005449

Photophysical characterization and BSA interaction of the direct ring carboxy functionalized unsymmetrical NIR cyanine dyes 査読有り

Maryala Saikiran, Daisuke Sato, Shyam S Pandey, Takeshi Ohta, Shuzi Hayase, Tamaki Kato

Dyes and Pigments   140   6 - 13   2017年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.dyepig.2017.01.015

Kyutacar

その他リンク： http://www.sciencedirect.com/science/article/pii/S0143720816307975

Transparent conductive oxide-less back contact dye-sensitized solar cells using flat titanium sheet with microholes for photoanode fabrication 査読有り

Hayat A., Hayat A., Baranwal A., Nakamura M., Shigeki F., Pandey S., Ma T., Hayase S.

Journal of Photonics for Energy   7 ( 1 )   2017年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Society of Photo-Optical Instrumentation Engineers (SPIE). A flat titanium sheet with microholes (FTS-MH) has been utilized to fabricate transparent conductive oxide-less dye-sensitized solar cells (TCO-less DSSCs) in back contact device architecture. Utilization of FTS-MH to fabricate a TCO-less photoanode offers several advantages in terms of simplicity and ease of fabrication as compared with the TCO-less DSSCs structure reported previously. Hydrogen peroxide (H 2 O 2 ) surface treatments on FTS-MH have shown important factors to enhance the photoanode properties. H 2 O 2 surface treatment is able to change the surface morphology of FTS-MH, and the created anatase titanium dioxide (TiO 2 ) nanostructures increase the surface contact between the FTS-MH and the coated mesoporous TiO 2 . Electrochemical impedance investigations reveled that improvements of the FTS-MH/TiO 2 and TiO 2 /dye/electrolyte interface led to hampered charge recombination resulting in enhancement of both short-circuit current density and open-circuit voltage, respectively. Even after removal of both TCO layers, our complete TCO-less DSSCs exhibited a power conversion efficiency of 7.25% under simulated solar irradiation.

DOI： 10.1117/1.JPE.7.015501

Scopus

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Transparent conductive oxide-less dye-sensitized solar cells consisting of dye-cocktail and cobalt based redox electrolyte 査読有り

Molla M., Baranwal A., Pandey S., Ma T., Hayase S.

Journal of Nanoscience and Nanotechnology   17 ( 7 )   4748 - 4754   2017年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Copyright © 2017 American Scientific Publishers. All rights reserved. Thin Ti-metal protected stainless steel metal mesh coated with mesoporous TiO 2 as flexible photoanode has been used to fabricate back contact transparent conductive oxide-less dye-sensitized solar cells. TiO 2 nanoparticle having a particle size of 15-20 nm sensitized with dye cocktail of two indoline dyes D-205 and D-131 were first utilized owing to their complementary light harvesting properties. Short-circuit photocurrent density (J sc ) for the dye cocktail combination of D-205 and D-131 (1:1) was found to be increased due to the increased photon harvesting in the 400-500 nm mainly associated with the contribution from D-131 dye. In addition, the electron recombination was suppressed when dye cocktail was employed as confirmed by the dark current measurement leading to higher open-circuit voltage (V oc ). The enhanced J sc accompanied with increased V oc resulted in to an improved efficiency of 3.59% for this cocktail combination. To enhance the efficiency even further, we have utilized TiO 2 nanoparticle having a larger particle size of 30 nm facilitating the mass transport of the bulky [Co(bpy) 3 ] 3+/2+ redox species. In order to enhance the photon harvesting window TiO 2 nanoparticles were sensitized with porphyrin dye (YD2-o-C8) along with different dye cocktail combinations with another complementary dye (Y123). Utilization of a dye cocktail of YD2-o-C8 and Y123 (4:1) led to improved photoconversion efficiency of 5.25% under simulated solar irradiation.

DOI： 10.1166/jnn.2017.13746

Scopus

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Influence of backbone structure on orientation of conjugated polymers in the dynamic casting of thin floating-films 査読有り

Pandey M., Pandey S., Nagamatsu S., Nagamatsu S., Hayase S., Hayase S., Takashima W., Takashima W.

Thin Solid Films   619   125 - 130   2016年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2016 Elsevier B.V. Dynamic casting of conjugated polymer films on liquid-substrate is a unique method which provides thin floating-film and can be easily transferred on a desired substrate by stamping. The important feature in this procedure is associated with the formation of thin polymeric film during compression and solidification controlled by viscous drag of liquid substrate and solvent evaporation of the polymer, respectively. Lyotropic liquid-crystalline (LC) characteristics of conjugated polymer possibly assist to orient the polymer chain in one direction. It is found that this method produce highly oriented thin films (dichroic ratio >  5) of thiophene-based conjugated polymers such as PBTTT-C14, PQT-C12 and non-regiocontrolled poly(3-hexylthiophene) NR-P3HT. On the other hand, weak orientation intensity in regioregular poly(3-hexylthiophene) RR-P3HT was found. The mechanism for this diverse orientation in thiophene-based conjugated polymers is discussed in correlation with the backbone chemical structure and lyotropic LC phase transition during the floating-film formation.

DOI： 10.1016/j.tsf.2016.11.015

Scopus

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Facile Synthesis and Characterization of Sulfur Doped Low Bandgap Bismuth Based Perovskites by Soluble Precursor Route 査読有り

Murugan Vigneshwaran, Takeshi Ohta, Satoshi Iikubo, Gaurav Kapil, Teresa S Ripolles, Yuhei Ogomi, Tingli Ma, Shyam S Pandey, Qing Shen, Taro Toyoda, Kenji Yoshino, Takashi Minemoto, Shuzi Hayase

Chemistry of Materials   28 ( 18 )   6336 - 6340   2016年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.chemmater.6b02315

その他リンク： http://pubs.acs.org/doi/abs/10.1021/acs.chemmater.6b02315

Enhancement of carrier mobility along with anisotropic transport in non-regiocontrolled poly (3-hexylthiophene) films processed by floating film transfer method 査読有り

Manish Pandey, Shuichi Nagamatsu, Shyam S Pandey, Shuzi Hayase, Wataru Takashima

Organic Electronics   38   115 - 120   2016年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.orgel.2016.08.003

その他リンク： http://www.sciencedirect.com/science/article/pii/S156611991630341X

Indoor Light Performance of Coil Type Cylindrical Dye Sensitized Solar Cells 査読有り

Gaurav Kapil · Yuhei Ogomi · Shyam S. Pandey · Tingli Ma · Shuzi Hayase ·

Journal of Nanoscience and Nanotechnology   16 ( 4 )   3183 - 3187   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1166/jnn.2016.12324

Scopus

Effect of Addition of KI on the Hydrothermal Growth of ZnO Nanostructures Towards Hybrid Optoelectronic Device Applications 査読有り

Anubha bilgaiyan · Tejendra Dixit · Gaurav Kapil · Shyam S Pandey · Shuji Hayase Iyamperumal Anand Palani · Vipul Singh ·

Journal of Nanoscience and Nanotechnology   16 ( 4 )   3301 - 3306   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1166/jnn.2016.12316

Parametric Optimization of Experimental Conditions for Dye-Sensitized Solar Cells based on Far-red Sensitive Squaraine Dye 査読有り

Takuya Morimoto, Naotaka Fujikawa, Yuhei Ogomi, Shyam S. Pandey, Shuzi Hayase

Journal of Physics:Conference Series   704   012002-1 - 012002-7   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012002

Kyutacar

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Tandem Dye-Sensitized Solar Cells Based on TCO-less Back Contact Bottom Electrodes 査読有り

Ajay K. Baranwal, Naotaka Fujikawa, Terumi Nishimura, Yuhei Ogomi, Shyam S. Pandey, Tingli Ma and Shuzi Hayase

Journal of Physics:Conference Series   704   012003-1 - 012003-8   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012003

Kyutacar

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Orientation Characteristics of Non-regiocontrolled Poly (3-hexyl-thiophene) Film by FTM on Various Liquid Substrates 査読有り

M Pandey, S Nagamatsu, S S Pandey, S Hayase and W Takashima

Journal of Physics:Conference Series   704   012005-1 - 012005-7   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012005

Kyutacar

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Photophysical investigations of squaraine and cyanine dyes and their interaction with bovine serum albumin 査読有り

M Saikiran, D Sato, S S Pandey and T Kato

Journal of Physics:Conference Series   704   012012-1 - 012012-10   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012012

Scopus

A Special Section on Recent Progress in Nano-Molecular Electronics 査読有り

Katsuhiko Ariga, Takaaki Manaka, Shyam S Pandey

Journal of Nanoscience and Nanotechnology   16 ( 4 )   3157 - 3158   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1166/jnn.2016.12275

Scopus

Design of far-red sensitizing squaraine dyes aiming towards the fine tuning of dye molecular structure 査読有り

Morimoto T., Fujikawa N., Ogomi Y., Pandey S., Ma T., Hayase S.

Journal of Nanoscience and Nanotechnology   16 ( 4 )   3282 - 3288   2016年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Copyright © 2016 American Scientific Publishers. All rights reserved. Model squaraine dyes having sharp and narrow absorptions mainly in the far-red wavelength region has been logically designed, synthesized and used for their application as sensitizer in the dye-sensitized solar cells (DSSC). In order to have fine control on energetics, dyes having same mother core and alkyl chain length varying only in molecular symmetry and position of substituent were designed. It has been found that even keeping all other structural factor constant, only positional variation of substituent leads to not only in the variation of energetics by 0.1 eV but affects the photovoltaic characteristics also. Optimum concentration of dye de-aggregating agent was found to be 100 times with respect to the sensitizing dye concentration. Amongst dyes utilized in this work best performance was obtained for unsymmetrical dye SQ-40 giving a photoconversion efficiency of 4.01% under simulated solar irradiation at global AM 1.5.

DOI： 10.1166/jnn.2016.12304

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Enhancing the performance of transparent conductive oxide-less back contact dye-sensitized solar cells by facile diffusion of cobalt species through TiO2 nanopores 査読有り

Md Zaman Molla, Minobu Kawano, Ajay K Baranwal, Shyam S Pandey, Yuhei Ogomi, Tingli Ma, Shuzi Hayase

RSC Advances   6 ( 40 )   33353 - 33360   2016年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c6ra04894c

Scopus

その他リンク： http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra04894c/unauth#!divAbstract

First principles analysis of oxygen vacancy formation and migration in Sr 2 BMoO 6 (B= Mg, Co, Ni) 査読有り

Shuai Zhao, Liguo Gao, Chunfeng Lan, SHYAM S PANDEY, Shuji Hayase and Tingli Ma

RSC Advances   6 ( 38 )   31968 - 31975   2016年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/C6RA05581H

その他リンク： http://pubs.rsc.org/is/content/articlelanding/2016/ra/c6ra05581h/unauth#!divAbstract

First principles analysis of oxygen vacancy formation and migration in Sr<inf>2</inf>BMoO<inf>6</inf> (B = Mg, Co, Ni) 査読有り

Zhao S., Gao L., Lan C., Pandey S., Hayase S., Ma T.

RSC Advances   6 ( 38 )   31968 - 31975   2016年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© The Royal Society of Chemistry 2016. Molybdenum-based double perovskites have been extensively studied as electrode materials in solid oxide fuel cells (SOFCs) due to their mixed ionic/electronic conductivity (MIEC) characteristics. Since the ionic conductivity in perovskite crystals arises primarily from oxygen ion diffusion via a vacancy-hopping mechanism, both the formation energy of the oxygen vacancy and the migration energy barrier play an essential role in the MIEC performance. In this work, we present a detailed first-principles investigation on the stoichiometric and oxygen-deficient structures of double perovskites, Sr 2 BMoO 6 (B = Mg, Co and Ni), using the density functional theory (DFT) method plus Hubbard U for Co and Ni. The electronic ground states of the oxygen-stoichiometric cells exhibited apparent eigenvalue gaps which are consistent with the measured insulating features. The oxygen-deficient structures were studied by removing a neutral oxygen atom according to SOFC working conditions, and the minimum energy path (MEP) of oxygen ion migration was optimized using the nudged elastic band (NEB) method which produced the theoretical migration energy barriers at the DFT+U level. The vacant oxygen sites released electrons to the adjacent cation d states, coupled with the delocalization characteristics of the Mo 4d state, which led eventually to the transition from an insulator to the electronic conductivity of the oxygen-deficient crystals. The electronic structure analysis suggested that the outer shell electrons of Mg, Co and Ni significantly affected the energies of oxygen vacancy formation and migration. Our results elucidate the effect of B-site substitution elements on the electronic properties and MIEC characteristics which provides theoretical support for the enhancement of the MIEC properties for these Mo-based double perovskites.

DOI： 10.1039/c6ra02297a

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Oxygen vacancy formation and migration in double perovskite Sr<inf>2</inf>CrMoO<inf>6</inf>: A first-principles study 査読有り

Zhao S., Gao L., Lan C., Pandey S., Hayase S., Ma T.

RSC Advances   6 ( 49 )   43034 - 43040   2016年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© The Royal Society of Chemistry 2016. The perovskite-type oxide ABO 3 with mixed ionic and electronic conductivity (MIEC) is a promising candidate for electrode materials of the intermediate-temperature solid oxide fuel cells (IT-SOFCs). The strontium molybdate SrMoO 3 shows high electrical conductivity but low oxygen ionic conductivity due to the stoichiometric features of oxygen. To enhance the oxygen ions diffusion rate, B-site Mo 4+ cation was partially substituted by trivalent transition metals (TM) to generate the oxygen-deficient double perovskite Sr 2 BMoO 6-δ . In this study, we present the theoretical investigation of the oxygen vacancy properties of Sr 2 CrMoO 6 (SCM) using density functional theory (DFT) with on-site Coulomb potential U for the Cr 3d electrons. The oxygen vacancy formation and migration were investigated for the B-site-ordered SCM, as well as the SCM with Cr/Mo antisite defects (ADs). The oxygen ion migration was optimized by the climbing image nudged elastic band (CINEB) method to identify the minimum energy pathway. The B-site Cr/Mo ADs allow various TM-O bond types in the double perovskite SCM. The calculated formation energy and migration barrier suggests that the B-site Cr/Mo ADs are favorable to enhance the oxygen ionic conductivity of the SCM. These results elucidate the influence of B-site Cr and Mo cations on the oxygen vacancy formation and migration in the double perovskite SCM, which can be useful for investigating Cr-doped SrMoO 3 as an IT-SOFCs anode.

DOI： 10.1039/c6ra05581h

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Effect of Varying Alkyl Chain Length on Thermal Decomposition Temperature of Zinc (II) Xanthates and its Impact on Curing of Epoxy Resin 査読有り

Tarun Chand Vagvala*, Shyam Sudhir Pandey, Suvratha Krishnamurthy and Shuzi Hayase

Zeitschrift für anorganische und allgemeine Chemie   642 ( 2 )   134 - 139   2015年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/zaac.201500639

Scopus

その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/zaac.201500639/full

Effects of different chloride precursors on crystal growth of lead halide perovskites 査読有り

Vigneshwaran Murugan, Yuhei Ogomi, Shyam S Pandey, Taro Toyoda, Qing Shen, Shuzi Hayase

Applied Physics Express   8 ( 12 )   125501-1 - 125501-4   2015年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.7567/APEX.8.125501

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CiNii Article

Relationship between diffusion of Co 3+/Co 2+ redox species in nanopores of porous titania stained with dye molecules, dye molecular structures, and photovoltaic performances 査読有り

Minobu Kawano, Tsubasa Nishiyama, Yuhei Ogomi, Shyam S Pandey, Tingli Ma, Shuzi Hayase

RSC Advances   5 ( 102 )   83725 - 83731   2015年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c5ra11992h

Scopus

Combining novel device architecture and NIR dye towards the fabrication of transparent conductive oxide-less tandem dye sensitized solar cells 査読有り

Ajay Kumar Baranwal, Naotaka Fujikawa, Azwar Hayat, Yuhei Ogomi, Shyam S Pandey, Tingli Ma, Shuzi Hayase

Applied Physics Express   8 ( 10 )   102301-1 - 102301-３   2015年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.7567/APEX.8.102301

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CiNii Article

Investigation of metal xanthates as latent curing catalysts for epoxy resin via formation of in-situ metal sulfides 査読有り

Tarun Chand Vagvala, Shyam Sudhir Pandey, Yuhei Ogomi, Tingly Ma, Shuzi Hayase

INORGANICA CHIMICA ACTA   435   292 - 298   2015年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.ica.2015.07.020

First principles study on the electronic and optical properties of B-site ordered double perovskite Sr 2 MMoO 6 (M= Mg, Ca, and Zn) 査読有り

Shuai Zhao, Chunfeng Lan, Jie Ma, Shyam S Pandey, Shuzi Hayase, Tingli Ma

Solid State Communications   213-214   19 - 23   2015年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.ssc.2015.04.012

Scopus

その他リンク： http://www.sciencedirect.com/science/article/pii/S0038109815001465#

Simple Metal-Free Dyes from Triphenylamine for DSSC: A Comparative Study of Two Different Anchoring Groups

K. Narayanaswami, T. Swetha, Gaurav Kapil, Shyam S. Pandey, Shuzi Hayase and Surya Prakash Singh

Electrochimica Acta   169   256 - 263   2015年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.electacta.2015.04.071

Scopus

その他リンク： http://www.sciencedirect.com/science/article/pii/S0013468615009639

Nonisothermal curing kinetics of epoxy resin composite utilizing Ga (III) xanthate as a latent catalyst 査読有り

Tarun Chand Vagvala*, Gaurav Kapil, Shyam S. Pandey, Yuhei Ogomi and Shuzi Hayase*

Journal of Applied Polymer Science   132 ( 26 )   42149-1 - 42149-7   2015年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/app.42149

Scopus

その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/app.42149/full

Dye-sensitized solar cells based on axially ligated phosphorus-phthalocyanine dyes 査読有り

Azwar Hayat, Gururaj M Shivashimpi, Terumi Nishimura, Naotaka Fujikawa, Yuhei Ogomi, Yoshihiro Yamaguchi, Shyam S Pandey, Tingli Ma, Shuzi Hayase

Applied Physics Express   8 ( 4 )   047001-1 - 047001-4   2015年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.7567/APEX.8.047001

Scopus

CiNii Article

その他リンク： http://iopscience.iop.org/1882-0786/8/4/047001

Complete Photodynamics of the Efficient YD2-o-C8 Based Solar Cell 査読有り

Piotr Piatkowski, Cristina Martin, Maria Rosaria di Nunzio, Boiko Cohen, Shyam S Pandey, Shuzi Hayase, Abderrazzak Douhal

Piotr Piatkowski, Cristina Martin, Maria Rosaria di Nunzio, Boiko Cohen, Shyam S Pandey, Shuzi Hayase, Abderrazzak Douhal   118   29674 - 29687   2014年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp510761z

Scopus

A COMBINED THEORETICAL AND EXPERIMENTAL APPROACHES TOWARDS DESGNING NIR DYES FOR DYE-SENSITIZED SOLAR CELLS 査読有り

YOSHIHIRO YAMAGUCHI, SHYAM S. PANDEY, NAOTAKA FUJIKAWA, YUHEI OGOMI, SHUZI HAYASE

Journal of Engineering Science and Technology   9   53 - 66   2014年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A combined theoretical and experimental approaches towards designing nir dyes for dye-sensitised solar cells 査読有り

Yamaguchi Y., Pandey S., Fujikawa N., Ogomi Y., Hayase S.

Journal of Engineering Science and Technology   9 ( Spec. Issue on Applied Engineering and Sciences (SAES2013), October 2014 )   51 - 65   2014年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© School of Engineering, Taylor’s University. Sensitizing dyes especially having capability of sharp light absorption in the near infrared region play a pivotal role towards enhancing the photovoltaic efficiency of dye-sensitised solar cells. Effort has been directed towards the optimization of suitable calculation parameters for the theoretical calculations to assist the design of novel sensitizers for the dye-sensitised solar cells using Gaussian program package. Suitability of the calculation parameters as well as calculated results using the same model, unsymmetrical squaraine dye (SQ-1) was designed, synthesized and used for their characterisation and photovoltaic applications. Calculation results were performed in both ground and excited states of this molecule and indicate that B3LYP and B3PW91 are quite suitable hybrid functional for theoretical calculation using DFT and 6-311G basis set. Electronic absorption maximum for SQ-A in ethanol solution exhibits the peak at 650 nm which was found to be only 47 nm (0.04 eV) higher as compared to the calculated value (603 nm) using PCM solvent model under TD-DFT.

Scopus

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Titanium wire engineering and its effect on the performance of coil type cylindrical dye sensitized solar cells 査読有り

Gaurav Kapil, Shyam S Pandey, Yuhei Ogomi, Tingli Ma, Shuzi Hayase

Organic Electronics   15   3399 - 3405   2014年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.orgel.2014.09.023

Scopus

Tandem dye-sensitized solar cells with a back-contact bottom electrode without a transparent conductive oxide layer 査読有り

AK Baranwal, T Shiki, Y Ogomi, SS Pandey, T Ma, S Hayase

RSC Advances   4   47735 - 47742   2014年09月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c4ra07539k

Scopus

Transparent conductive oxide-less back contact dye-sensitized solar cells using cobalt electrolyte 査読有り

Md. Zaman Molla, Norihiro Mizukoshi, Hiroaki Furukawa, Yuhei Ogomi, Shyam S. Pandey, Tingli Ma and Shuzi Hayase

Progress in Photovoltaic Research and Applications   2014年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/pip.2526

Scopus

Graphene Oxide Based Biosensor for Food Toxin detection 査読有り

Saurabh Srivastava, Md. Azahar Ali, Seema Umrao, Upendra Parashar, Anchal Srivastava, Gajjala Sumana, B. D. Malhotra, Shyam Sudhir Pandey and Shuzi Hayase

Applied Biochemistry and Biotechnology   174   960 - 970   2014年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1007/s12010-014-0965-4

Scopus

Template Assisted Electrochemical Growth of Polypyrrole Nanotubes for Development of High Sensitivity Glucose Biosensor 査読有り

Pragya Agar Palod, Shyam S. Pandey, Shuzi Hayase and Vipul Singh

Applied Biochemistry and Biotechnology   174   1059 - 1072   2014年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1007/s12010-014-0988-x

Scopus

Far-Red Sensitizing Octatrifluorobutoxy Phosphorous Triazatetrabenzo-corrole: Synthesis, Spectral Characterization and Aggregation Studies 査読有り

Gururaj M. Shivashimpi, Shyam S. Pandey, Azwar Hayat, Naotaka Fujikawa, Yuhei Ogomi, Yoshihiro Yamaguchi, Shuzi Hayase

Journal of Photochemistry and Photobiology A:Chemistry   289   53 - 59   2014年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.jphotochem.2014.05.011

Scopus

Gallium (III) xanthate as a novel thermal latent curing agent for epoxy resin composite 査読有り

Tarun Chand Vagvala, SHYAM S PANDEY, Yuhei Ogomi, Shuji Hayase

RSC Advances   4   24658 - 24661   2014年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c4ra03151b

All solid perovskite solar cells with HOCO-R-NH3I anchor group inserted between porous TiO2 and perovskite 査読有り

Yuhei Ogomi, Atsushi Morita, Shota Tsukamoto, Takahiro Saitho, Qing Shen, Taro Toyoda, Kenji Yoshino, Shyam S. Pandey, Tingli Ma and Shuzi Hayase;

Journal of Physical Chemistry C   118 ( 30 )   16651 - 16659   2014年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp412627n

Scopus

Fabrication and characterization of coil type transparent conductive oxide less cylindrical dye-sensitized solar cells 査読有り

Gaurav Kapil, Jin Ohara, Yuhei Ogomi, SHYAM S PANDEY, Tingli Ma and Shuzi Hayase

RSC Advances   4   22959 - 22963   2014年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c4ra02999b

Scopus

Spectroscopy and Dynamics of YD2-o-C8 in Solution and Interacting with Alumina Nanoparticles Electrode 査読有り

Maria Rosaria di Nunzio, Boiko Cohen, Shyam S. Pandey, Shuzi Hayase, Giovanni Piani, and Abderrazzak Douhal

Journal of Physical Chemistry C   118   11365 - 11376   2014年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp503449q

Scopus

Transparent conductive oxide-less back contact dye-sensitized solar cells using Zinc porphyrin dye employing cobalt complex redox shuttle 査読有り

Molla M., Pandey S., Ogomi Y., Ma T., Hayase S.

2014 IEEE 40th Photovoltaic Specialist Conference, PVSC 2014   1538 - 1542   2014年01月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2014 IEEE. A transparent conductive oxide-less (TCO-less) dye-sensitized solar cell (DSSC) consisting of back-contacted stainless steel metal mesh electrode has been fabricated. In this work, [Co(bpy) 3 ] 3+/2+ complex based redox electrolyte and porphyrin dye as sensitizer were utilized. Owing to relatively deeper redox energy level for cobalt based electrolytes as compared to I 3 - /I - redox system, possibility of obtaining high open-circuit voltage was explored. Employing a thin film of Ti on the metal mesh as the charge recombination blocking layer resulted in enhanced photoconversion efficiency. TCO-less DSSC in combination with cobalt electrolyte gave the power conversion efficiency of 4.89% under simulated solar irradiation.

DOI： 10.1109/PVSC.2014.6925209

Scopus

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Flexible transparent conductive oxide-less cylinder dyesensitized solar cells 査読有り

Usagawa J., Pandey S., Ogomi Y., Hayase S.

Advanced Optoelectronics for Energy and Environment, AOEE 2013   2013年11月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Dye sensitized solar cells which does not need transparent conductive oxide layered glass (TCO-less DSCs) are reviewed. Especially, flexible cylinder TCO-less DSCs with 5.1% efficiency is focused on. © OSA 2013.

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84887697352&origin=inward

Dye sensitized solar cells consisting of metallophthalocyanine axially anchored on metal oxide nanoparticles through metal-o-metal linkages-difference in photovoltaic performances between TiO<inf>2</inf> and SnO<inf>2</inf> electrode 査読有り

Park B., Shen Q., Shen Q., Ogomi Y., Pandey S., Toyoda T., Hayase S.

ECS Journal of Solid State Science and Technology   2 ( 1 )   2013年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

High performance SnO 2 -based bottom electrodes are necessary for tandem dye-sensitized solar cells (DSSCs) harvesting infrared (IR) lights. Sensitizing dyes based on macrocyclic ligands are one of the candidates among the IR dyes. However, it is difficult to introduce anchoring groups such as carboxylic acid at the right position of macrocyclic rings where electron injection occurs. It was proved that axially anchored phthalocyanines (model compounds) bonded to SnO 2 nanoparticle surfaces with short metal-O-metal linkage inject electrons from dyes to SnO 2 layers spatially, because themacrocyclic rings are very close to SnO 2 surfaces. TiO 2 based DSSCs did not show photovoltaic properties because of very fast charge recombination between injected electrons and oxidized dyes which were measured by a transient absorption spectroscopy technique. In the case of SnO 2 -based DSSC, the charge recombination was slower than that of the TiO 2 -based DSSCs, which enabled the collection of electrons. Since this anchoring system can be prepared easily, it is a good strategy for use in the design of near-IR absorbing dye. © 2012 The Electrochemical Society.

DOI： 10.1149/2.014301jss

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84887416199&origin=inward

Effect of extended π-conjugation on photovoltaic performance of dye sensitized solar cells based on unsymmetrical squaraine dyes 査読有り

Pandey S., Watanabe R., Fujikawa N., Shivashimpi G., Ogomi Y., Yamaguchi Y., Hayase S.

Tetrahedron   69 ( 12 )   2633 - 2639   2013年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Aiming toward the far-red to near infra-red (NIR) photon harvesting, three new unsymmetrical squaraine dyes bearing direct ring carboxy functionalized indole as an anchoring moiety with varying donor groups with extended π-conjugation have been successfully synthesized and utilized for dye sensitized solar cell fabrication. Under simulated solar irradiation, dye SQ-8 gave a photoconversion efficiency of 3.3% mainly harvesting photons in the far-red region between 500 and 700 nm. By extending the π-conjugation of the donor moieties in the novel unsymmetrical squaraine dyes, it was possible to extend the light absorption from far-red to NIR wavelength region. In spite of good light absorption up to 900 nm and energetic matching, dye SQ-16 was found to exhibit the decreased photon harvesting, which was explained by the enhanced dye aggregation along with its difficulty in facile electron injection as indicated from electronic absorption spectroscopic and DFT calculation results, respectively. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2013.01.036

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84874117228&origin=inward

Effect of extended p-conjugation on photovoltaic performance of dye-sensitized solar cells based on unsymmetrical squaraine dyes 査読有り

Shyam S. Pandey, Rie Watanabe, Naotaka Fujikawa, Gururaj M. Shivashimpi, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

Tetrahedron   69   2633 - 2639   2013年01月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Electrophoretic deposition onto an insulator for thin film preparation toward electronic device fabrication 査読有り

Shougo Miyajima, Shuichi Nagamatsu, Shyam S. Pandey, Shuzi Hayase, Keiichi Kaneto and Wataru Takashima

Applied Physics Letters   101   193305-1 - 193305-4.   2012年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1063/1.4766126

Scopus

Dye sensitized solar cells consisting of metallophthalocyanines axially anchored on metal-oxide nanoparticles through Metal-O-metal linkages-Difference in photovoltaic performances between TiO2 and SnO2 electrodes 査読有り

Byung-wook Park, Qing Shen, Yuhei Ogomi, Shyam S. Pandey, Taro Toyoda and Shuzi Hayase.

ECS Journal of Solid-State Science and Technology   2 ( 1 )   Q6 - Q11   2012年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Dye-Sensitized Solar Cells based on Novel Far-red Sensitizing Unsymmetrical Squaraine Dye containing Pyrroloquinoline Moiety 査読有り

Shyam S. Pandey, Naotaka Fujikawa, Rie Watanabe, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

Japanese Journal of Applied Physics; Vol. 51, No.-10, Issue-2, pages 10NE12-1-10NE12-5.   51 ( 10 )   10NE12-1 - 10NE12-5   2012年10月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Differences in Dye-Sensitized Photovoltaic Behaviours between SnO2 and TiO2 Electrodes 査読有り

Kengo Sadamasu, Yuhei Ogomi, Shyam S. Pandey and Shuzi Hayase

Japanese Journal of Applied Physics   51 ( 10 )   10NE05-1 - 10NE05-5   2012年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/JJAP.51.10NE05

Scopus

CiNii Article

Relating the Photodynamics of Squaraine-Based Dye-Sensitized Solar Cells to the Molecular Structure of the Sensitizers and to the Presence of Additives 査読有り

G. de Miguel, M. Marchena, B. Cohen, S. S. Pandey, S. Hayase and A. Douhal

Journal of Physical Chemistry-C   116 ( 42 )   22157 - 22168   2012年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp306125y

Scopus

Dye sensitized solar cells based on novel far red sensitizing unsymmetrical squaraine dye containing pyrroloquinoline moiety 査読有り

Pandey S., Fujikawa N., Watanabe R., Ogomi Y., Yamaguchi Y., Hayase S.

Japanese Journal of Applied Physics   51 ( 10 PART 2 )   2012年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A novel far-red sensitive and direct aromatic ring carboxy functionalized unsymmetrical squaraine dye based on pyrroloquinoline moiety has been synthesized for the application as sensitizer of dye sensitized solar cells. This dye bearing the characteristics of both of indole and quinoline moieties exhibits the photon harvesting up to 820 nm. The enhancement in the photon harvesting window by the pyrroloquinoline based squaraine dye was attributed to the presence of increased π-conjugation in its pyrroloquinoline donor part. This pyrroloquinoline bearing unsymmetrical squaraine dye exhibits a short circuit current density of 9.88 mA/cm2, an open circuit voltage of 0.57 V and fill factor of 0.59 leading to the external power conversion efficiency of 3.33% under simulated solar irradiation of 100mW/cm2 at AM 1.5 condition. © 2012 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.51.10NE12

Scopus

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Back contact dye-sensitized solar cells of various shapes without transparent conducing oxides (TCO-less DCCSs)-

Jun Usagawa, Takeshi Kougo, Yuhei Ogomi, Shyam S. Pandey and Shuzi Hayase

Trends in Advanced Sensitized and Organic Solar Cells   2012年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Solution processable thin film organic photovoltaic cells based on far red sensitive2 soluble squaraine dye 査読有り

Shyam S. Pandey, Takafumi Mizuno, Sandeep K. Das, Yuhei Ogomi and Shuzi Hayase.

Thin Solid Films   522   401 - 406   2012年08月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2012.08.043

Scopus

Novel unsymmetrical squaraine dye bearing cyanoacrylic acid anchoring group and its photosensitization behaviour 査読有り

Gururaj M. Shivashimpi, Shyam S. Pandey, Rie Watanabe, Naotaka Fujikawa, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

Tetrahedron Letters   53 ( 40 )   5437 - 5440   2012年07月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tetlet.2012.07.125

Scopus

Femto- to millisecond photophysical characterization of indole-based squaraines adsorbed on TiO <inf>2</inf> nanoparticle thin films 査読有り

De Miguel G., Marchena M., Ziółek M., Pandey S., Hayase S., Douhal A.

Journal of Physical Chemistry C   116 ( 22 )   12137 - 12148   2012年06月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

In this paper, we address femto- to millisecond transient absorption studies of TiO 2 nanoparticle (NP) thin films sensitized with four squaraine (SQ) molecules, with and without a deaggregating agent, chenodeoxycholic acid (CDCA). On the femto- to picosecond time scale, we determined the presence of three transient species by using singular value decomposition (SVD) analysis, i.e., S 1 of the SQ monomers, S 1 of the SQ H-aggregates, and the SQ radical cation formed after the electron injection. Both monomers and H-aggregates are proven to inject electrons to the TiO 2 conduction band, being 5 times faster in the monomers (e.g., k ei mon = 5.1 × 10 11 s -1 and k ei H-agg = 1.1 × 10 11 s -1 for SQ 41). Besides, the undesired singlet-singlet annihilation is an active process in these samples, constituting the drain of a high percentage of the absorbed photons. The coadsorption of CDCA on the TiO 2 NP avoids the formation of H-aggregates, and therefore, only two transient species are present in these samples: S 1 of the monomer and the SQ radical cation with k ei mon = 6.7 × 10 11 s -1 for SQ 41. On the microsecond scale, we only observed the transient feature of the radical cation of the SQ that permits one to study its recombination dynamics. Similar lifetimes (94-150 μs) of the four SQ radial cations are obtained when only monomers are present in the sample. In the absence of CDCA, the presence of H-aggregates contributes to shorten the lifetime of the radical cation (e.g., from 110 to 45 μs in the case of SQ 41). This fact can be explained by considering a stronger electronic coupling of H-aggregates/TiO 2 surface with respect to the monomers. These results explore the photodynamics of this family of SQs adsorbed on TiO 2 NP in a very large time window and will enable a better understanding of the influence of aggregates in the kinetics of these SQs used as sensitizers in DSSCs. © 2012 American Chemical Society.

DOI： 10.1021/jp302928f

Scopus

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Femto to Millisecond Photophysical Characterization of Indole-based Squaraines Adsorbed on TiO2 Nanoparticle Thin Films. 査読有り

de Miguel, Gustavo; Marchena, Maria Jose; Ziolek, Marcin; Pandey, Shyam; Hayase, Shuzi; Douhal, Abderrazzak

Journal of Physical Chemistry-C;   116 ( 22 )   12137 - 12148   2012年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

その他リンク： https://pubs.acs.org/journal/jpccck

Flexible Transparent Conductive Oxide-less Flat and Cylinder Dye-Sensitized Solar Cells 査読有り

Jun Usagawa, Takeshi Kougo, Kengo Sadamasu, Shyam S. Pandey, Yuhei Ogomi and Shuzi Hayase

Journal of Photonics for Energy   2 ( 1 )   021011-1 - 021011-10   2012年05月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1117/1.JPE.2.021011

Scopus

Photophysics of H-and J-aggregates of Indole based squaraines in solid state. 査読有り

G. de Miguel, M. Ziolek, M, Zitnan, J. A. Organero, S. S. Pandey, S Hayase and A. Douhal

Journal of Physical Chemistry-C   116 ( 17 )   9379 - 9389   2012年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp210281z

Scopus

その他リンク： https://pubs.acs.org/journal/jpccck

Multiple electron injection dynamics in linearly linked two dye-co-sensitized nanocrystalline metal oxide electrode for dye sensitized solar cells;; 査読有り

Qing Shen, Y. Ogomi, Byung-wook Park, Takafumi Inoue, Shyam S. Pandey, Akari Miyamoto, Shinsuke Fujita, Kenji Katayama, Taro Toyoda and Shuzi Hayase

Physical Chemistry and Chemical Physics   14   4605 - 4613   2012年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c2cp23522f

Scopus

Transparent conductive oxide less flexible dye-sensitized solar cells with flat and cylinder shapes 査読有り

Usagawa J., Park B., Ogomi Y., Pandey S., Hayase S.

Materials Research Society Symposium Proceedings   1435 ( January )   51 - 54   2012年01月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2012 Materials Research Society. Transparent conductive oxide less flexible dye-sensitized solar cells (TCO-less DSC) with flat and cylinder shapes are reported. The cell consists of a plastic cover, a flexible titania/dye sheet back contacted with a metal mesh sheet, a gel electrolyte sheet, and Pt layer on a Ti sheet. How to increase the efficiency were discussed. We concluded that making a titania/dye layer on a metal mesh sheet thinner and using a thinner electrolyte layer were effective for increasing the efficiency. A flat TCO-less DSC with 6.1 % efficiency and a cylindrical TCO-less DSC with 5.1 % efficiency are reported.

DOI： 10.1557/opl.2012.1695

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Femto to millisecond observations of indole-based squaraines molecules photodynamics in Solution 査読有り

G. de Miguel, M. Marchena, M. Ziolek, M, Zitnan, S. S. Pandey, S Hayase and A. Douhal

Physical Chemistry and Chemical Physics   2011年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c1cp22864a

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その他リンク： http://pubs.rsc.org/en/content/articlelanding/2012/cp/c1cp22864a

Multiple electron injection from dyes to titania layer for high efficiency-dye-sensitized solar cells 査読有り

Park B., Sadamasu K., Ogomi Y., Miyamoto A., Fujita S., Pandey S., Shen Q., Shen Q., Toyoda T., Hayase S.

Conference Record of the IEEE Photovoltaic Specialists Conference   001187 - 001191   2011年12月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

We report two kinds of dye-sensitized solar cells where multiple electron injection mechanism is used. One is multiple electron injection consisting of linearly linked two dye molecules. Tin(IV) 2,11,20,29-tetra-tert-butyl-2,3- naphthalocyanine (NcSn) was adsorbed on a SnO 2 surface by a Sn(p)-O-Sn(n) linkage, where Sn(p) and Sn(n) stand for a Sn atom on a Sn nanoparticle surface and that at the center of NcSn, respectively. Cis-diisothiocyanato- bis(2,2′-bipyridyl-4,4′-dicarboxylato) ruthenium(II) bis(tetrabutylammonium), known as N719, was bonded to NcSn by a-Sn(n)-O-CO-linkage. The incident photon to photocurrent efficiency (IPCE) curve of the cell (DD-cell) suggested that electrons are injected from both N719 and NcSn to SnO 2 nanoparticles. The mechanism was supported by transient absorption spectra studies. The other is multiple electron injection from double titania layer (top and bottom layers). The top and bottom electrodes were stained with different dyes having different λ max. A top layer fabricated on a glass was mechanically pressed with a bottom layer fabricated on a glass cloth to fabricate an anode. The glass cloth acts as a supporter of a porous titania layer as well as a holder of electrolyte. The incident photon to current efficiency (IPCE) curve had two peaks corresponding to those of the two dyes, which demonstrates that electrons are collected from both the top and bottom layers. © 2011 IEEE.

DOI： 10.1109/PVSC.2011.6186168

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Transparent Conductive Oxide-less thee-dimentional cylindrical dye-sensitized solar cell fabricated with flexible metal mesh electrode 査読有り

Jun Usagawa, Shyam S. Pandey, Yuhei Ogomi, Sho Noguchi, Yoshihiro Yamaguchi and Shuzi Hayase

Progress in Photovoltaics Research and Applications   2011年11月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/pip.1223

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その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/pip.1223/full

Aiming at high efficiency dye-sensitized solar cells - From the view point of photoconversion interface 査読有り

Hayase S., Ogomi Y., Pandey S.

Electrochemistry   79 ( 10 )   761 - 764   2011年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Researches aiming at high efficiency-dye-sensitized solar cells (DSC) are reviewed from the view point of photoconversion interfaces. Developments of dyes converting photons to electrons in near infrared regions are essential for increasing short circuit current (Jsc). Hybrid cells consisting of double dye structures and double titania layer structures are proposed. Leak currents at photoconversion interfaces decrease open circuit voltage (Voc) and fill factor (FF). Therefore, strategies for decreasing leak currents are essential, especially for all-solid DSCs and IVLf free DSCs. Structures of these interfaces are discussed in terms of surface passivation, self-organization, dye structures, interactions between dyes and I3 - in titania nanopores. Fundamental studies for tandem cells are also reported.

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Fine tuning the structure of unsymmetrical squaraine dyes towards the development of efficient dye sensitized solar cells 査読有り

Shyam S. Pandey, Rie Watanabe, Naotaka Fujikawa, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

SPIE Proceeding   8111   811116-1 - 811116-9   2011年09月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

USA   Sandiego, LA   2011年08月21日  -  2011年08月26日

DOI： 10.1117/12.893354

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その他リンク： http://dx.doi.org/10.1117/12.893354

Investigating the Role of Dye Dipole on Open Circuit Voltage in Solid-State Dye-Sensitized Solar Cells 査読有り

Shyam S Pandey, Kyung-Young Lee, Azwar Hayat, Yuhei Ogomi, and Shuzi Hayase

Japanese Journal of Applied Physics   50 ( 6 )   06GF08-1 - 06GF08-4   2011年06月

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/JJAP.50.06GF08

Scopus

CiNii Article

Transparent conductive oxideless tandem dye-sensitized solar cells consisting of light-splitting structures 査読有り

Jun Usagawa,Masaki Kaya,Yuhei Ogomi,Shyam S. Pandey,and Shuzi Hayase

Journal of Photonics for Energy   1 ( 1 )   011110 - 1   2011年03月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1117/1.3555458

Scopus

Hybrid Dye-Sensitized Solar Cells Consisting of Double Titania Layers for Harvesting Light with Wide Range of Wavelengths 査読有り

Kengo Sadamasu,Takafumi Inoue,Yuhei Ogomi,Shyam S. Pandey,and Shuzi Hayase

Applied Physics Express   4 ( 2 )   022301 - 1   2011年01月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/APEX.4.022301

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CiNii Article

TCO-less 3D-DYE-sensitized solar cells consisting of charge separation sheet and direction to high efficiency cells by using TCO-less structure 査読有り

Usagawa J., Uzaki K., Pandey S., Ogomi Y., Yamaguchi Y., Kono M., Hayase S.

Conference Record of the IEEE Photovoltaic Specialists Conference   518 - 522   2010年12月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Three dimensional transparent conductive oxide-less dye-sensitized solar cells (3D-TCO-less DSCs) consisting of a flexible porous titania sheet are reported. The flexible titania sheet is composed of a dye stained porous titania layer and a mesh sheet acting as the backbone. Flexible TCO-less DSCs, tandem DSCs, TCO-less cylinder DSCs and TCO-Iess cubic DSCs are fabricated and their fundamental photovoltaic performances are reported. © 2010 IEEE.

DOI： 10.1109/PVSC.2010.5616802

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Electron Injection from Linearly Linked Two Dye Molecules to Metal Oxide Nanoparticles for Dye Sensitized Solar Cells Covering Wavelength Range from 400-950 nm 査読有り

Byung-wook Park,Takafumi Inoue,Yuhei Ogomi,Akari Miyamoto,Shinsuke Fujita,Shyam S. Pandey and Shuzi Hayase

Applied Physics Express   4 ( 1 )   012301 - 1   2010年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/APEX.4.012301

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CiNii Article

Tandem dye-sensitized solar cells consisting of floating electrode in one cell 査読有り

Uzaki K., Pandey S., Hayase S.

Journal of Photochemistry and Photobiology A: Chemistry   216 ( 2-3 )   104 - 109   2010年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Tandem dye-sensitized solar cells (Cell TAN) consisting of a floating electrode (bottom cell) and a TiO 2 electrode prepared on a F-doped SnO 2 glass (top cell) are reported. The floating electrode is a flexible and self-standing composite film consisting of a porous titania/dye layer supported by a mesh electrode. The floating electrode was inserted between the TiO 2 electrode and the counter electrode in a conventional single dye-sensitized solar cell to fabricate the Cell TAN. Therefore, the Cell TAN is completely different from previously reported tandem cells where two cells are merely accumulated and connected to each other. The Incident Photon to Current Conversion Efficiency (IPCE) curve for the Cell TAN had two peaks corresponding to those of the two single cells. The open circuit voltage (V oc ) of the Cell TAN (0.88 V) was higher than that of the corresponding single cell (0.6-0.66 V). These two results strongly demonstrated that the Cell TAN has a potential for tandem cells. © 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jphotochem.2010.07.025

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TCO-less 3D dye-sensitized solar cells consisting of charge separation sheet -tandem, hybrid, cylinder and fiber cells- 査読有り

Usagawa J., Uzaki K., Kaya M., Kougo T., Pandey S., Ogomi Y., Yamaguchi Y., Kono M., Hayase S.

2010 10th IEEE Conference on Nanotechnology, NANO 2010   171 - 175   2010年12月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Three dimensional transparent conductive oxide-less dye-sensitized solar cells (3D-TCO-less DSCs) consisting of a flexible porous titania sheet are reported. The flexible titania sheet is composed of a dye stained porous titania layer and a mesh sheet acting as the backbone. Flexible TCO-less DSCs, tandem DSCs, TCO-less cylinder DSCs and TCO-less cubic DSCs are fabricated and their fundamental photovoltaic performances are reported. ©2010 IEEE.

DOI： 10.1109/NANO.2010.5698067

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Solvation Effect on the Ion Exchange in Polypyrrole Film doped with Sulfonated Polyaniline 査読有り

Wataru Takashima,Hikaru Hashimoto,Kazuo Tominaga,Akihisa Tanaka,Shyam S. Pandey and Keiichi Kaneto

Thin Solid Films, Vol. 519, pp. 1093-1099 (2010).   519   1093 - 1099   2010年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2010.08.050

Scopus

Probing Mechanism of Dye Double Layer Formation from Dye Cocktail Solution for Dye Sensitized Solar Cells 査読有り

Yuhei Ogomi,Shyam S. Pandey,Shunta Kimura and Shuzi Hayase

Thin Solid Fims   519   1087 - 1092   2010年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2010.08.049

Scopus

Tandem Dye-Sensitized Solar Cells Consisting of Nanoporous Titania Sheet 査読有り

Kenshiro Uzaki,Shyam S. Pandey,Yuhei Ogomi and Shuzi Hayase

Japanese Journal of Applied Physics, Vol. 49, No.-6, pp. 062301 (2010).   49 ( 6 )   082301 - 1   2010年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/JJAP.49.082301

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CiNii Article

Alkyl and Fluoro-alkyl Substituted Squaraine Dyes: A Prospective Approach Towards Development of Novel NIR Sensitizers 査読有り

Shyam S. Pandey,Takafumi Inoue,Naotaka Fujikawa,Yoshihiro Yamaguchi and Shuzi Hayase

Thin Solid Films   519   1066 - 1071   2010年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2010.08.045

Scopus

Tandem Dye Sensitized Solar Cells Consisting of Floating Electrode in One Cell 査読有り

Kenshiro Uzaki,Shyam S. Pandey,and Shuzi Hayase

Journal of Photochemistry and Photobiology A: Chemistry   216 ( 1 )   104 - 109   2010年08月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Substituent Effect in Direct Ring Functionalized Squaraine Dyes on Near Infra-Red Sensitization of NanocrystallineTiO2 for Molecular Photovoltaics 査読有り

Shyam S. Pandey,Takafumi Inoue,Naotaka Fujikawa,Yoshihiro Yamaguchi and Shuzi Hayase

Journal of Photochemistry and Photobiology A: Chemistry, Vol. 214, pp. 269-275 (2010)   214 ( 2-3 )   268 - 275   2010年07月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.jphotochem.2010.07.010

Scopus

Synthesis and characterization of squaric acid based NIR dyes for their application towards dye sensitized solar cells 査読有り

Takafumi Inoue,Shyam S. Pandey,Naotaka Fujikawa,Yoshiro Yamaguchi and Shuzi Hayase

Journal of Photochemistry and Photobiology A: Chemistry, Vol 213, pp. 23-29 (2010).   213 ( 1 )   23 - 29   2010年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.jphotochem.2010.04.015

Scopus

Tandem Dye Sensitized Solar Cells Consisting of Floating Electrode Supported by Non-Conductive Glass Mesh 査読有り

Kenshiro Uzaki,Shyam S. Pandey,Yuhei Ogomi and Shuzi Hayase

Advances in Science and Technology   74   157 - 163   2010年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Influence of nature of surface dipoles on observed photovoltage in dye-sensitized solar cells as probed by surface potential measurements 査読有り

Shyam S. Pandey,Shohei Sakaguchi,Yoshiro Yamaguchi,Shuzi Hayase

Organic Electronics   11 ( 3 )   419 - 426   2009年11月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

主要雑誌

DOI： 10.1016/j.orgel.2009.11.021

Scopus

Role of morphology on Photoluminescence quenching and depletion width formed at the interface of Aluminum and Poly(3-Alkylthiophene） 査読有り

Vipul Singh,Shyam S Pandey,Wataru Takashima,and Keiichi Kaneto

Japanese Journal of Applied Physics   41 ( 6 )   061503 - 1   2009年06月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

Tandem Dye-Sensitized Solar Cells Fabricated on Glass Rod without Transparent Conductive Layers 査読有り

Jun Usagawa,Shyam S. Pandey,Shuzi Hayase,Mitsuru Kono,and Yoshihiro Yamaguchi

Applied Physics Express   2 ( 6 )   062203 - 1   2009年06月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

主要雑誌

Transparent Conductive Oxide layer-less dye-sensitized solar Cells consisting of floating electrode with gradient TiOx layer 査読有り

パンディ　シャム　スディル

Applied Physics Letters   94   093301 - 093301   2009年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Preparation of Double Dye-Layer Structure of Dye-Sensitized Solar Cells from Cocktail Solutions for Harvesting Light in Wide Range of Wavelengths 査読有り

パンディ　シャム　スディル

Japanese Journal of Applied Physics   48 ( 2 )   020213 - 020213   2009年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Optical and Electrical Characterization of Poly(3-hexylthiophene-2,5-diyl) Interface with Al and LiF 査読有り

パンディ　シャム　スディル

Japanese Journal of Applied Physics   47 ( 2B )   1251 - 1255   2008年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Characterization of Depletion Layer using Photoluminescence Technique 査読有り

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Applied Physics Express   1 ( 2 )   021801 - 021801   2008年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A comparative study of Al and LiF:Al interfaces with Poly (3-Hexylthiophene) using bias dependent photoluminescence technique 査読有り

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Organic Electronics   9 ( 5 )   790 - 796   2008年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Solvation contribution on the ion exchange in polypyrrole films doped with sulfonated polyaniline 査読有り

パンディ　シャム　スディル

Physical Chemistry and Chemical Physics   2008年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Evidence of Photoluminescence Quenching in Poly (3-hexylthiophene-2,5-diyl)due to injected charge carriers 査読有り

パンディ　シャム　スディル

Synthetic Metals   158 ( 7 )   283 - 286   2008年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Probing TiO2/dye Interface in Dye Sensitized Solar Cells using Surface Potential Measurement 査読有り

パンディ　シャム　スディル

Applied Physics Express   1 ( 10 )   105001 - 105001   2008年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Role of morphology on Photoluminescence quenching and depletion width formed at the interface of Aluminum and Poly(3-Alkylthiophene) 査読有り

パンディ　シャム　スディル

Japanese Journal of Applied Physics   2008年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Synthetic and Characterization of Dendritic Poly(L-lysine) containing Porphyrin-Fullerene Moieties 査読有り

パンディ　シャム　スディル

Synthetic Metals   157   311 - 317   2007年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Simultaneous co-immobilization of enzyme and a redox mediator in poly pyrrole film for the fabrication of an amperometric phenol biosensor 査読有り

パンディ　シャム　スディル

Current Applied Physics   5 ( 2 )   184 - 188   2005年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Patternable bi-ionic actuator: an example of new functionality of actuation, folding and unfolding of electrochemical spring 査読有り

パンディ　シャム　スディル

Sensors and Actuators B: Chemical   110 ( 1 )   120 - 124   2005年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Electrochemomechanical Deformation in Conducting Co-polymers containing Pyrrole and Anisidine Moieties 査読有り

パンディ　シャム　スディル

Reactive and Functional Polymers   58   103 - 110   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Development of Amperometric Biosensor Based on Redox Mediator doped Polypyrrole Films 査読有り

パンディ　シャム　スディル

Journal of Applied Polymer Science   93   927 - 933   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Enhanced Electrochemomechanical Deformation of Polyaniline Film by Optimization of pH and Electrolyte Concentration 査読有り

パンディ　シャム　スディル

Trans. Material Research Society   229 ( 3 )   771 - 774   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Conserved Electrochemomechanical Activities of Polypyrrole Films in Complex Buffer Media 査読有り

パンディ　シャム　スディル

Sensors & Actuators B: Chemical   102   142 - 147   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Improved Cathodic Expansions of Electrochemomechanical behavior of Polypyrrole Films Electrodeposited from Aerosol OT Emulsion 査読有り

パンディ　シャム　スディル

Chemistry Letters   33   996 - 996   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Electrochemically Generated Deformation of Polyaniline Film Plasticized with DI-2-butoxy, 2-ethoxy ester of Sulfosuccinic acid 査読有り

パンディ　シャム　スディル

Sensors & Actuators B: Chemical   99   601 - 607   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Electrochemomechanical Deformation studies of Hexacyanoferrate Ion doped Polypyrrole Film 査読有り

パンディ　シャム　スディル

Thin Solid Films   467   227 - 230   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Enhanced Electrochemomechanical Activities of Polyaninile Films Towards High pH Region: Contribution of Donnan Effect 査読有り

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Electrochimica Acta   49   4239 - 4244   2004年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Investigation of bi-ionic Contribution for enhancement of Bending Actuation in Polypyrrole Film 査読有り

パンディ　シャム　スディル

Sensors & Actuators B: (Chemical)   89   48 - 52   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Effect of Disorder on the Magnetic States in Pol(3-hexylthiophene) 査読有り

パンディ　シャム　スディル

Synthetic Metals   135-136   343 - 343   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Bi-Ionic Actuators by Polypyrrole Films 査読有り

パンディ　シャム　スディル

Synthetic Metals   135-136   61 - 61   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Enhanced Electrochemomechanical Behaviors of Polyanilne Films by Chloride Concentrations 査読有り

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Chemistry Letters   32 ( 11 )   990 - 990   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photovoltaic Properties in Poly(3-alkylthiophene) based Heterojunction Cells 査読有り

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Current Applied Physics   3 ( 2-3 )   107 - 113   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Proposal of Novel Actuators Using Conducting Polymer Laminates 査読有り

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Synthetic Metals   135-136   135 - 135   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Structure-Property Correlation: Electrochemomechanical Deformation in Polypyrrole Films 査読有り

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Thin Solid Films   438-439   206 - 211   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Immobilization of Glucose Oxidase on to Langmuir Blodgett Films Poly(3-hexylthiophene) 査読有り

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Current Applied Physics   3 ( 2-3 )   275 - 279   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Effect of Film Morphology on the Actuation Behavior in Polypyrrole Films 査読有り

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Synthetic Metals   135-136   59 - 59   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Cyclic-voltammetry and electrochemomechanical deformation of freestanding polypyrrole film in diluted media 査読有り

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Thin Solid Films   438-439   339 - 345   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Temperature Dependence of Rectification and Photovoltaic Effects in Regioregular Poly(3-alkylthiophene) films at the Schottky Junction of Al Electrode 査読有り

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Current Applied Physics   3 ( 2-3 )   321 - 324   2003年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Electrochemomechanical Deformation of Polypyrrole Film in Complex Buffer Media 査読有り

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IPMM CD Book   2003年04月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

2003年04月  -  2003年04月

Cyclic Step-voltammetric Analysis of Cation-driven and Anion-driven Actuuation in Polypyrrole Films 査読有り

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Japanese Journal of Applied Physics   41   7532 - 7536   2002年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier Transport Modulated by Film Morphology in Regioregular Poly(3-hexyl thiophene) 査読有り

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Thin Solid Films   393   334 - 342   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier Generation in Regioregular Poly(3-alkylthiophene) Photovoltaic Cells 査読有り

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Synthetic Metals   121   1565 - 1565   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier Mobility in Poly(2-methoxyaniline) 査読有り

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Journal of Applied Polymer Science   79 ( 8 )   1506 - 1512   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photovoltaic Cell using High Mobility Poly(alkylthiophene)s and TiO2 査読有り

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Synthetic Metals   121   1537 - 1537   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Poly(3-Butylthiophene):Conjugated Polymer with Record High TOF Mobility 査読有り

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Synthetic Metals   121   1561 - 1561   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Dispersivity of Carrier Transport related with Molecular Arrangement in Regioregular Poly(3-alkylthiophene) 査読有り

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Synthetic Metals   119   563 - 563   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier Transport in Non-Uniform Field Based on Schottky Cell for the Time-of-Flight Measurements Poly(3-alkyl thiophene) Films 査読有り

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Japanese Journal of Applied Physics   40 ( 8 )   4933 - 4937   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Effect of Regioregularity on carrier transport in Poly(alkylthiophene) films with various alkyl chain lengths 査読有り

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Current Applied PhysICW   1 ( 1 )   90 - 97   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier Transport in Regioregular Poly(3-octadecylthiophene) 査読有り

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Japanese Journal of Applied Physics   40   5350 - 5356   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier Transport in Processable Poly(3-alktlthiophenes) 査読有り

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Synthetic Metals   121   1563 - 1563   2001年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Morphology Effect on Photocarrier Transport in Regioregular Poly(3-alkylthiphene) Films

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IEICE-OME   ED-2001   41 - 47   2001年04月

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記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）

Thermal Analysis of Chemically Synthesized Polyemeraldine Base 査読有り

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Journal of Applied Polymer Science   75 ( 1 )   145 - 149   2000年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Mechanism of Photocarrier Generation and Transport in Poly(3-alkylthiophene) films 査読有り

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Japanese Journal of Applied Physics   39   6309 - 6315   2000年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Effect of Synthetic Impurities on Photocarrier Transport in Poly(3-hexylthiophene) 査読有り

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IEICE Transactions on Electronics   E-83 ( 7 )   1088 - 1093   2000年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Role of Processing Solvents in Photocarrier Transport of Polyaniline 査読有り

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Japqnese Journal of Applied Physics   39 ( 7A )   4445 - 4450   2000年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Regioregularity Vs Regiorandomness: Effect on Photocarrier Transport in Poly(3-hexyl thiophene) 査読有り

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Japanese Journal of Applied Physics   39   94 - 97   2000年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Covalent Immobilization of Glucose Oxidase to Poly(o-aminobenzoic acid) for application to Glucose Biosensor 査読有り

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Journal of Applied Polymer Science   78 ( 3 )   662 - 667   2000年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Time of Flight Mobility of Poly(3-alkylthiophenes) 査読有り

W. Takashima,S. S. Pandey,M. Rikukawa,and K. Kaneto

Technical report of IEICE   OME99 ( 231 )   29 - 34   2000年04月

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記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

Photocarrier Transport Phenomena in Polythiophene derivatives 査読有り

S. Nagamatsu,Shyam S. Pandey,W. Takashima,K. Kaneto

Pusan-Kyeongnam/Kyushu-Seibu joint International Symposium   14 - 14   1999年11月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

Seoul (South Korea)   Chinju   1999年11月02日  -  1999年11月03日

Carrier Mobility of Conducting Polymers 査読有り

W. Takashima,S. Nagamatsu,W. Y. Lim,K. Endo,M. Kaneko,S. S. Pandey and K. Kaneto

Pusan-Kyeongnam/Kyushu-Seibu joint International Symposium   1999年11月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

South Korea   Chinju   1999年11月02日  -  1999年11月03日

Effect of Regiospecificity on Photocarrier Mobility in Poly(3-hexylthiophene 査読有り

Shyam S. Pandey,S. Nagamatsu,M. Kaneko,W. Takashima,M. Rikukawa and K. Kaneto

Pusan-Kyeongnam/Kyushu-Seibu joint International Symposium   1999年11月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

South Korea   Chinju   1999年11月02日  -  1999年11月03日

未入力 査読有り

M. Kaneko,Shyam S. Pandey,K. Takayama,S. Nagamatsu,Lim W. Y,W. Takashima,K. Kaneto and M. Rikukawa

未入力   1999年11月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

South Korea   Chinju   1999年11月02日  -  1999年11月03日

Time-of-Flight Photocarrier Mobility in Langmuir-Blodgett Films of Regioregular Poly(3-hexyl thiophene 査読有り

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Japanese Journal of Applied Physics   38   6768 - 6771   1999年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier Mobility in Regioregular Poly(3-hexylthiophene) Studied by Time-of-Flight Method 査読有り

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Japaneswe Journal of Applied Physics   38   1188 - 1190   1999年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

TOF Mobility in Poly(3-hexylthiophene)

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IEICE-OME-99   17   29 - 29   1999年04月

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記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）

Dielectric relaxation in thin conducting polyaniline films 査読有り

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Polymer   39 ( 15 )   3399 - 3404   1998年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Electrical Properties of Metal(Indium)/PolyanilineSchottky devices 査読有り

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Journal of Applied Polymer Science   65   2745 - 2745   1997年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A.C. Conductivity of Polyemeraldine Base 査読有り

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Journal of Physics Condensed Matter   6   8913 - 8922   1994年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Optical and Electrical Characteristics of the Electrodeposited Polypyrrole Films 査読有り

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Journal of Applied Polymer Science   50 ( 3 )   411 - 411   1993年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Muon studies of conducting polymers 査読有り

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Synthetic Metals   55   677 - 677   1993年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Photocarrier mobility in processable polyaniline 査読有り

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Journal of Applied Physics   74   2109 - 2109   1993年04月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

1993年04月  -  1993年04月

Synthesis and Characterization of Poly(aniline-co-orthoanisidine): A processable conducting polymer 査読有り

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Macromolecules   26   3190 - 3190   1993年04月

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

1993年04月  -  1993年04月

Vacuum Deposited Metal/Polyaniline Schottky Diode 査読有り

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Applied Physics Letters   61   1219 - 1219   1992年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Some recent studies on Metal/polyaniline Schottky devices; 査読有り

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Journal of Applied Polymer Science   44 ( 5 )   911 - 911   1992年04月

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記述言語：英語   掲載種別：研究論文（学術雑誌）