Faculty Profiles - PANDEY Shyam sudhir

Papers - PANDEY Shyam sudhir

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Fabrication of Nanobioengineered Interfaces Utilizing Quaternary Nanocomposite for Highly Efficient and Selective Electrochemical Biosensing of Urea Reviewed International journal

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

Langmuir ( American Chemical Society ) 2024.09

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

High-Density, Nonvolatile, Flexible Multilevel Organic Memristor Using Multilayered Polymer Semiconductors Reviewed International journal

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 2024.04

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://pubs.acs.org/doi/10.1021/acsami.4c03111

Photophysical Characterization and Biointeractions of NIR Squaraine Dyes for in Vitro and in Vivo Bioimaging Reviewed International journal

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 2023.12

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

Yuki Kurokawa, Takehito Kato, Shyam S. Pandey

Physica Status Solidi-A ( Wiley ) 220 ( 24 ) 2300116 (1) - 2300116 (7) 2023.08

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed International journal

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) 2023.08

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： https://www.sciencedirect.com/science/article/pii/S1385894723026633

Smart Alginate Nanomaterials: Revolutionizing Food Across Delivery, Preservation, Packaging, Safety, and Waste Upcycling Reviewed International journal

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

Carbohydrate Polymer Technologies and Applications ( Elsevier ) 2024.09

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S2666893924001488?via%3Dihub

Probing heavy metals in tropospheric particulate matter – An approach towards sustainability Reviewed International journal

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) 2024.08

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Materials Today Electronics ( Elsevier ) 9 100112(1) - 100112(11) 2024.08

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

Kota Mori, Yuki Kurokawa and Shyam S. Pandey*

Colorants ( MDPI ) 3 ( 3 ) 198 - 216 2024.07

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： https://www.mdpi.com/2079-6447/3/3/14

Synthesis and advances of smart heteroatom-sited coatings for anticorrosion applications Reviewed

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) 2024.07

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

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

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

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Highest anticorrosive property was shown by epoxy-CoO nanomaterial.

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 Reviewed International journal

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

Environmental Research ( Elsevier ) 259 119435(1) - 119435(23) 2024.06

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S0013935124013409?via%3Dihub

Role of Si and SiO2 in Optoelectronic Device Fabrication Reviewed International journal

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

Journal of Molecular Structure ( Elsevier ) 1316 138994(1) - 138994(9 2024.06

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed

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

Optical Materials ( Elsevier ) 153 115535(1) - 115535(10) 2024.05

Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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) Reviewed International journal

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

Micromachine ( MDPI ) 15 ( 6 ) 677(1) - 677(16) 2024.05

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Proliferating optoelectronic properties of doped ZnO nanoparticles Reviewed International journal

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)) 2024.04

Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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. Reviewed International journal

Sai Kiran Mavileti, Tamaki Kato, Shyam S. Pandey

Journal of Molecular Structure ( Elsevier ) 1309 138226(1) - 138226(9) 2024.04

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S0022286024007464?via%3Dihub

Targeted elimination of heavy metals from industrial wastewater: Synergistic effect of nano metal oxides Reviewed International journal

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) 2024.03

Language：English Publishing type：Research paper (scientific journal)

Design and synthesis of pro-active nano metal oxides.

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Advanced and cost-effective process for water treatment.

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

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

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

Other Link： 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 Reviewed International journal

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 2024.03

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Molecules ( MDPI ) 29 ( 6 ) 1282(1) - 1282(14) 2024.03

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Polymers ( MDPI ) 16 ( 5 ) 710(1) - 710(13) 2024.03

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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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

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Other Link： 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 Reviewed International journal

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 2024.02

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://pubs.rsc.org/en/content/articlelanding/2024/nj/d4nj00061g

Hetero atom-based metal complexes as emitters in organic light-emitting diodes Reviewed International journal

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

Journal of Molecular Structure ( Elsevier ) 1304 137664(1) - 137664(13) 2024.01

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

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Controlling adsorption of two dyes on TiO2 surface to improve the efficiency of see-through dye-sensitized solar cells Reviewed International journal

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

Solar Energy ( Elsevier ) 269 112339(1) - 112339(11) 2024.01

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

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Fabrication of All-Polymer Organic Phototransistors Utilizing Oriented P3HT Reviewed

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)) 2023.12

Language：English Publishing type：Research paper (scientific journal)

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

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Other Link： https://ieeexplore.ieee.org/document/10376029

Enhancement in Capacitance of Ionic Type of EAP-Based Strain Sensors Reviewed International journal

Nitin KUMAR Singh, Kazuto Takashima, Shyam S Pandey

Sensors ( MDPI ) 23 ( 23 ) 9400(1) - 9400(19) 2023.11

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Colorants ( MDPI ) 2 ( 4 ) 654 - 673 2023.11

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

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Other Link： 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 Reviewed International journal

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

Physica Status Solidi-A ( Wiley ) 220 ( 24 ) 2300166 (1) - 2300166 (8) 2023.10

Language：English Publishing type：Research paper (scientific journal)

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

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Other Link： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300166

Bioinspired Multifunctional Silver Nanoparticles for Optical Sensing Applications: A Sustainable Approach Invited Reviewed International journal

Kshitij RB Singh, Arunadevi Natarajan, Shyam S. Pandey

https://doi.org/10.1021/acsabm.3c00669 ( American Chemical Society ) 6 ( 11 ) 4549 - 4571 2023.10

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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) 2023.10

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

International Journal of Biological Macromolecules ( Elsevier ) 253 ( 8 ) 127587(1) - 127587(12) 2023.09

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S0141813023044859?via%3Dihub

Symbiotic study of N-bridged metal complexes as electrocatalysts for hydrogen evolution reaction Reviewed International journal

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

International Journal of Hydrogen Energy ( Elsevier ) 52 ( A ) 1458 - 1471 2023.08

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

Suraya Shaban, Safalmani Pradhan, Shyam S. Pandey

Physica Status Solidi-A ( Elsevier ) 220 ( 24 ) 2300241 (1) - 2300241 (7) 2023.08

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

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Other Link： 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 Reviewed International journal

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

Journal of Materials Chemistry C ( RSC ) 11 12364 - 12373 2023.08

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Physica Status Solidi-A ( Wiley ) 220 ( 24 ) 2023.08

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

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Other Link： 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 Reviewed International journal

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

Materials ( MDPI ) 16 5249(1) - 5249(12) 2023.07

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

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Other Link： 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 Reviewed International journal

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) 2023.07

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Physica Status Solidi-A ( Elsevier ) 220 ( 24 ) 2300194 (1) - 2300194 (7) 2023.07

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed International journal

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) 2023.07

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

Pritha Roy, Yuki Kurokawa, Shyam S. Pandey

Physica Status Solidi-A ( Wiley ) 220 ( 4 ) 2300158 (1) - 2300158 (8) 2023.06

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed International journal

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) 2023.06

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed International journal

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

Physica Status Solidi-A ( Wiley ) 220 ( 4 ) 2300095(1) - 2300095(7) 2023.06

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

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

Design and Synthesis of Novel Squaraine Dye with Highly Enhanced Far‐Red Fluorescence and its Interaction with a Model Protein Reviewed International journal

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

Physica Status Solidi-A ( Wiley ) 220 ( 24 ) 2300226(1) - 2300226(8) 2023.06

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://onlinelibrary.wiley.com/doi/10.1002/pssa.202300226

Bistable Resistive Memory Switches Fabricated by Floating Thin Films of Conjugated Polymers Reviewed International journal

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

Materials Today Electronics ( Elsevier ) 4 100043(1) - 100043(1) 2023.06

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed International journal

Yuki Kurokawa, Takehito Kato, Shyam S. Pandey

Synthetic Metals ( Elsevier ) 220 117362(1) - 117362(8)) 2023.05

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： https://www.sciencedirect.com/science/article/pii/S037967792300084X?via%3Dihub

3. Design and Synthesis of Novel NIR Sensitive Unsymmetrical Squaraine Dyes for Molecular Photovoltaics Reviewed

Safalmani Pradhan Yuki Kurokawa Shyam S Pandey

Physica Status Solidi-A ( Wiley ) 220 ( 24 ) 2300145(1) - 2300145(10) 2023.04

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Highly Conductive Graphenated-Carbon Nanotubes Sheet with Graphene Foliates for Counter Electrode Application in Dye-Sensitized Solar Cell Reviewed International journal

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 ) 2023.03

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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 2023.03

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

Suraya Shaban, Ajendra K Vats, Shyam S Pandey

Molecules ( MDPI ) 28 ( 6 ) 2784 2023.03

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed International journal

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 2023.02

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Applied Surface Science ( Elsevier ) 616 156377 2023.01

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S0169433223000533

Cylindrical transparent conductive oxide-free dye-sensitized solar cells with treated flat titanium sheet Reviewed International journal

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

Journal of Photonics for Energy ( SPIE ) 2022.12

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Organic Electronics ( Elsevier ) 113 106691 2022.11

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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 Reviewed International journal

Nitin Kumar SINGH, Kazuto TAKASHIMA and Shyam S. PANDEY

Sensors and Transducers ( IFSA Publishing ) 259 ( 5 ) 12 - 18 2022.10

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (international conference proceedings)

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.

Other Link： 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 Reviewed International journal

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 2022.10

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Kyutacar

Other Link： 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+ Reviewed

Linjun Tang, Shubham Sharma, Shyam S Pandey

Molecules ( MDPI ) 27 ( 19 ) 6578 2022.10

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.mdpi.com/1420-3049/27/19/6578

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

Nitin Kumar Singh, Kazuto Takashima, Shyam Sudhir Pandey

Engineering Proceedings ( Multidisciplinary Digital Publishing Institute ) 21 ( 1 ) 2022.08

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (international conference proceedings)

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

Other Link： https://www.mdpi.com/2673-4591/21/1/1

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

Nitin Kumar Singh, Kazuto Takashima, Shyam S Pandey

Materials Today Communications ( Elsevier ) 32 104095 2022.07

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed

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

IEEE Explore ( IEEE ) 124 - 127 2022.07

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (international conference proceedings)

Japan http://www.amfpd.jp/ 2022.07.05 - 2022.07.08

DOI： 10.23919/AM-FPD54920.2022.9851297

Other Link： http://www.amfpd.jp/

Tear strength estimation of electroactive polymer-based strain sensors Reviewed

Nitin Kumar Singh, Kazuto Takashima, Shyam Sudhir Pandey

Electroactive Polymer Actuators and Devices (EAPAD) XXIIV ( SPIE ) 12042 424 - 428 2022.04

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (international conference proceedings)

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

Other Link： 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 Reviewed International journal

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

Japanese Journal of Applied Physics 61 ( SB ) SB1021-1 - SB1021-11- 2022.01

Charge transfer and catalytic properties of various PEDOTs as Pt-free counter electrodes for dye-sensitized solar cells Reviewed International journal

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

Japanese Journal of Applied Physics 61 ( SB ) SB1010-1 - SB10110-6 2022.01

Recent progress in the macroscopic orientation of semiconducting polymers by floating film transfer method, Reviewed International journal

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

Japanese Journal of Applied Physics 61 ( SB ) SB0801-1 - SB0801-12 2022.01

Bifacial dye-sensitized solar cells utilizing green colored NIR sensitive unsymmetrical squaraine dye Reviewed International journal

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

Japanese Journal of Applied Physics 61 ( SB ) SB1005-1 - SB1005-6 2022.01

A COMPARATIVE STUDY OF GRAPHENATED-CARBON NANOTUBES COTTON AND CARBON NANOTUBES AS CATALYSTS FOR COUNTER ELECTRODE IN DYE-SENSITIZED SOLAR CELLS Reviewed International journal

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

Malaysian Journal of Microscopy 2021.12

Language：English Publishing type：Research paper (scientific journal)

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.

Other Link： https://malaysianjournalofmicroscopy.org/ojs/index.php/mjm/index

Highly sensitive organic phototransistors fabricated from PCPDTBT: PCBM blend Reviewed International journal

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

Journal of Physics: Conference Series 2070 ( 1 ) 2021.11

Implication of color of sensitizing dyes on transparency and efficiency of transparent dye-sensitized solar cells Reviewed International journal

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

Solar Energy 225 950 - 960 2021.09

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

Yuki Kurokawa, Shuichi Nagamatsu, Shyam S Pandey

IEEE Explore ( IEEE ) 2021.08

Language：English Publishing type：Research paper (international conference proceedings)

Japan Conference: 28th International Workshop on Active Matrix, Flatpanel Displays and Devices (AM-FPD21)A 2021.06.29 - 2021.07.02

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

Other Link： https://ieeexplore.ieee.org/document/9499214

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

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

ACS Applied Materials & Interfaces ( American Chemical Society ) 2021.08

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://pubs.acs.org/doi/abs/10.1021/acsami.1c09671

Assisted alignment of conjugated polymers in floating film transfer method using polymer blend Reviewed

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

Thin Solid Films ( Elsevier ) 734 138814(1) - 138814(8 2021.07

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Physica Status Solidi (RRL) - Rapid Research Letters ( WILEY-V CH VERLAG GMBH ) 2021.06

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Synthetic Metals ( Synthetic Metals ) 278 116797(1) - 116797(11) 2021.05

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S0379677921001028

Development of PCPDTBT thin film based highly sensitive organic phototransistors Reviewed International journal

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

Materials Today' Proceeding ( Elsevier ) 2021.04

Language：English Publishing type：Research paper (international conference proceedings)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S2214785321025232?via%3Dihub

Fatigue life prediction of electroactive polymer strain sensor Reviewed

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) 2021.03

Language：English Publishing type：Research paper (international conference proceedings)

USA Sandiego, California 2021.03.22 - 2021.03.27

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

Other Link： 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 Reviewed International journal

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

Optical Materials ( Elsevier ) 113 110886(1) - 110886(9) 2021.03

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed International journal

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

Frontiers of Chemical Science and Engineering 16 ( 7 ) 1060 - 1078 2021.01

Investigation of Orientation in the Thin Films of Conjngated Polymer and NIR Dye Blends Fabricated by Friction Transfer Method Reviewed International journal

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 2021.01

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

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

ACS Applied Materials and Interfaces 12 ( 49 ) 55033 - 55043 2020.12

Language：English Publishing type：Research paper (scientific journal)

© 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

Other Link： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85097812392&origin=inward

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

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 2020.12

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

Nagamatsu S., Pandey S.S.

Scientific Reports 10 ( 1 ) 2020.12

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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

Journal of Photonics for Energy 10 ( 4 ) 2020.10

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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

ACS Applied Electronic Materials 2 ( 9 ) 2721 - 2729 2020.09

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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

Solar Energy 208 411 - 418 2020.09

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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 ) 2020.09

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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

Journal of Materials Science: Materials in Electronics 31 ( 18 ) 15277 - 15285 2020.09

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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 2020.09

Language：English Publishing type：Research paper (international conference proceedings)

© 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 Reviewed

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

Synthetic Metals 264 2020.06

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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

Journal of Photochemistry and Photobiology A: Chemistry ( Elsevier ) 394 112467(1) - 112467(12) 2020.03

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

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

Organic Electronics ( Elsevier ) 81 105683(1) - 105683(9) 2020.03

Investigation and control of charge transport anisotropy in highly oriented friction transferred polythiophene thin films Reviewed

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

ACS Applied Materials & Interfaces ( American Chemical Society ) 12 ( 10 ) 11876 - 11883 2020.02

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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 Reviewed

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

Japanese Journal of Applied Physics 59 ( SC ) 2020.02

Language：English Publishing type：Research paper (scientific journal)

© 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 Reviewed

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

Japanese Journal of Applied Physics ( IOP Science ) 69 ( SC ) SCCA06-1 - SCCA06-6 2019.11

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://iopscience.iop.org/article/10.7567/1347-4065/ab48b9/meta

P3HT Nanofibrils Thin-Film Transistors by Adsorbing Deposition in Suspension Reviewed

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

Materials ( MDPI ) 12 ( 21 ) 3643 2019.11

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.mdpi.com/1996-1944/12/21/3643

Clitoria ternatea flower as natural dyes for Dye-sensitized solar cells Reviewed

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 2019.10

Language：English Publishing type：Research paper (scientific journal)

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.

Kyutacar

Other Link： 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 Reviewed

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 2019.09

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://aip.scitation.org/doi/full/10.1063/1.5109083

Recent advances in the orientation of conjugated polymers for organic field-effect transistors Reviewed

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

Journal of Materials Chemistry ( Royal Society of Chemistry ) 7 13323 - 13351 2019.09

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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 Reviewed

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 2019.07

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： 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 Reviewed

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

Solar Energy Materials and Solar Cells ( Elsevier ) 195 122 - 133 2019.03

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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 Reviewed

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

Carbon ( Elsevier ) 147 252 - 261 2019.03

Language：English Publishing type：Research paper (scientific journal)

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

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Passivation of Grain Boundary by Squaraine Zwitterions for Defect Passivation and Efficient Perovskite Solar Cells Reviewed

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 2019.02

Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://pubs.acs.org/doi/abs/10.1021/acsami.8b22044

2D positional profiling of orientation and thickness uniformity in the semiconducting polymers thin films Reviewed

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

Organic Electronics ( Elsevier ) 68 221 - 229 2019.02

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S1566119919300746

Back-illuminated dye-sensitized solar cell flexible photoanode on titanium foil Reviewed

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 2019.01

Language：English Publishing type：Research paper (scientific journal)

© 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

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Synthesis, characterizations and photo-physical properties of novel lanthanum (III) complexes Reviewed

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 2018.11

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

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

Organic Electronics ( Elsevier ) 65 1 - 7 2018.10

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

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

Other Link： https://www.sciencedirect.com/science/article/pii/S1566119918305585

Synthesis and Optoelectrical Characterization of Novel Squaraine Dyes Derived from Benzothiophene and Benzofuran Reviewed

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 2018.10

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

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 2018.09

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

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

ACS Applied Energy Materials 1 ( 9 ) 4545 - 4553 2018.08

A review of transparent solar photovoltaic technologies Reviewed

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

Renewable and Sustainable Energy Reviews 94 779 - 791 2018.07

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

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

ACS Sustainable Chemistry & Engineering 6 ( 8 ) 10221 - 10228 2018.06

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

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

112 ( 12 ) 123301-1 - 123301-5 2018.03

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

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

Organic Electronics 56 152 - 158 2018.02

Rapid Formation and Macroscopic Self-Assembly of Liquid-Crystalline, High-Mobility, Semiconducting Thienothiophene Reviewed

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

Advanced Materials Interfaces 5 ( 6 ) 1700875(1) - 1700875(11) 2018.01

Casting Control of Floating-films into Ribbon-shape Structure by modified Dynamic FTM Reviewed

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

Journal of Physics: Conference Series 924 ( 1 ) 012014(1) - 012014(6) 2017.11

Photophysical Characterization and BSA Interaction of Direct Ring Carboxy Functionalized Symmetrical squaraine Dyes Reviewed

Maryala Saikiran, Shyam S Pandey, Shuzi Hayase, Tamaki Kato

Journal of Physics: Conference Series 924 ( 1 ) 012006(1) - 012006(10) 2017.11

Parametric Optimization of Dye-Sensitized Solar Cells Using Far red Sensitizing Dye with Cobalt Electrolyte Reviewed

A Pradhan, M Saikiran, G Kapil, S S Pandey, S Hayase

Journal of Physics: Conference Series 924 012001(1) - 012001(9) 2017.11

Investigation of the minimum driving force for dye regeneration utilizing model squaraine dyes for dye-sensitized solar cells Reviewed

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

Journal of Materials Chemistry A 5 ( 43 ) 22672 - 22682 2017.10

Efficient near infrared fluorescence detection of elastase enzyme using peptide-bound unsymmetrical squaraine dye Reviewed

Maryala Saikiran, Daisuke Sato, Shyam S Pandey, Shuzi Hayase, Tamaki Kato

Bioorganic & Medicinal Chemistry Letters 27 ( 17 ) 4024 - 4029 2017.07

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 Reviewed

246 243 - 251 2017.07

Investigation of Interfacial Charge transfer in Solution Processed Cs2SnI6 Thin Films Reviewed

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 2017.06

Interplay of Orientation and Blending: Synergistic Enhancement of Field Effect Mobility in Thiophene-Based Conjugated Polymers Reviewed

Manish Pandey, Shuichi Nagamatsu, Wataru Takashima, Shyam Sudhir Pandey, Shuzi Hayase

Journal of Physical Chemistry C 121 ( 21 ) 11184 - 11193 2017.05

Layer-by-layer coating of oriented conjugated polymer films towards anisotropic electronics Reviewed

227 29 - 36 2017.05

Solvent driven performance in thin floating-films of PBTTT for organic field effect transistor: Role of macroscopic orientation Reviewed

43 240 - 246 2017.04

Controlling factors for orientation of conjugated polymer films in dynamic floating-film transfer method Reviewed

17 ( 3 ) 1915 - 1922 2017.03

Transparent Conductive Oxide Layer and Hole Selective Layer Free Back-Contacted Hybrid Perovskite Solar Cell Reviewed

Zhaosheng Hu, Gaurav Kapil, Hiromitsu Shimazaki, Shyam Sudhir Pandey, Tingli Ma, Shuzi Hayase

The Journal of Physical Chemistry C 121 ( 8 ) 4214 - 4219 2017.02

Combined theoretical and experimental approaches for development of squaraine dyes with small energy barrier for electron injection Reviewed

Shyam S Pandey, Takuya Morimoto, Naotaka Fujikawa, Shuzi Hayase

Solar Energy Materials and Solar Cells 159 625 - 632 2017.01

Photophysical characterization and BSA interaction of the direct ring carboxy functionalized unsymmetrical NIR cyanine dyes Reviewed

Maryala Saikiran, Daisuke Sato, Shyam S Pandey, Takeshi Ohta, Shuzi Hayase, Tamaki Kato

Dyes and Pigments 140 6 - 13 2017.01

Transparent conductive oxide-less dye-sensitized solar cells consisting of dye-cocktail and cobalt based redox electrolyte Reviewed

17 ( 7 ) 4748 - 4754 2017.01

Transparent conductive oxide-less back contact dye-sensitized solar cells using flat titanium sheet with microholes for photoanode fabrication Reviewed

7 ( 1 ) 2017.01

Influence of backbone structure on orientation of conjugated polymers in the dynamic casting of thin floating-films Reviewed

619 125 - 130 2016.11

Facile Synthesis and Characterization of Sulfur Doped Low Bandgap Bismuth Based Perovskites by Soluble Precursor Route Reviewed

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 2016.09

Enhancement of carrier mobility along with anisotropic transport in non-regiocontrolled poly (3-hexylthiophene) films processed by floating film transfer method Reviewed

Manish Pandey, Shuichi Nagamatsu, Shyam S Pandey, Shuzi Hayase, Wataru Takashima

Organic Electronics 38 115 - 120 2016.08

Indoor Light Performance of Coil Type Cylindrical Dye Sensitized Solar Cells Reviewed

Gaurav Kapil · Yuhei Ogomi · Shyam S. Pandey · Tingli Ma · Shuzi Hayase ·

Journal of Nanoscience and Nanotechnology 16 ( 4 ) 3183 - 3187 2016.04

Effect of Addition of KI on the Hydrothermal Growth of ZnO Nanostructures Towards Hybrid Optoelectronic Device Applications Reviewed

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 2016.04

Parametric Optimization of Experimental Conditions for Dye-Sensitized Solar Cells based on Far-red Sensitive Squaraine Dye Reviewed

Takuya Morimoto, Naotaka Fujikawa, Yuhei Ogomi, Shyam S. Pandey, Shuzi Hayase

Journal of Physics:Conference Series 704 012002-1 - 012002-7 2016.04

Tandem Dye-Sensitized Solar Cells Based on TCO-less Back Contact Bottom Electrodes Reviewed

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 2016.04

Orientation Characteristics of Non-regiocontrolled Poly (3-hexyl-thiophene) Film by FTM on Various Liquid Substrates Reviewed

M Pandey, S Nagamatsu, S S Pandey, S Hayase and W Takashima

Journal of Physics:Conference Series 704 012005-1 - 012005-7 2016.04

Photophysical investigations of squaraine and cyanine dyes and their interaction with bovine serum albumin Reviewed

M Saikiran, D Sato, S S Pandey and T Kato

Journal of Physics:Conference Series 704 012012-1 - 012012-10 2016.04

A Special Section on Recent Progress in Nano-Molecular Electronics Reviewed

Katsuhiko Ariga, Takaaki Manaka, Shyam S Pandey

Journal of Nanoscience and Nanotechnology 16 ( 4 ) 3157 - 3158 2016.04

Design of far-red sensitizing squaraine dyes aiming towards the fine tuning of dye molecular structure Reviewed

16 ( 4 ) 3282 - 3288 2016.04

Enhancing the performance of transparent conductive oxide-less back contact dye-sensitized solar cells by facile diffusion of cobalt species through TiO2 nanopores Reviewed

Md Zaman Molla, Minobu Kawano, Ajay K Baranwal, Shyam S Pandey, Yuhei Ogomi, Tingli Ma, Shuzi Hayase

RSC Advances 6 ( 40 ) 33353 - 33360 2016.03

First principles analysis of oxygen vacancy formation and migration in Sr 2 BMoO 6 (B= Mg, Co, Ni) Reviewed

Shuai Zhao, Liguo Gao, Chunfeng Lan, SHYAM S PANDEY, Shuji Hayase and Tingli Ma

RSC Advances 6 ( 38 ) 31968 - 31975 2016.03

Oxygen vacancy formation and migration in double perovskite Sr<inf>2</inf>CrMoO<inf>6</inf>: A first-principles study Reviewed

6 ( 49 ) 43034 - 43040 2016.01

First principles analysis of oxygen vacancy formation and migration in Sr<inf>2</inf>BMoO<inf>6</inf> (B = Mg, Co, Ni) Reviewed

6 ( 38 ) 31968 - 31975 2016.01

Effect of Varying Alkyl Chain Length on Thermal Decomposition Temperature of Zinc (II) Xanthates and its Impact on Curing of Epoxy Resin Reviewed

Tarun Chand Vagvala*, Shyam Sudhir Pandey, Suvratha Krishnamurthy and Shuzi Hayase

Zeitschrift für anorganische und allgemeine Chemie 642 ( 2 ) 134 - 139 2015.11

Effects of different chloride precursors on crystal growth of lead halide perovskites Reviewed

Vigneshwaran Murugan, Yuhei Ogomi, Shyam S Pandey, Taro Toyoda, Qing Shen, Shuzi Hayase

Applied Physics Express 8 ( 12 ) 125501-1 - 125501-4 2015.11

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 Reviewed

Minobu Kawano, Tsubasa Nishiyama, Yuhei Ogomi, Shyam S Pandey, Tingli Ma, Shuzi Hayase

RSC Advances 5 ( 102 ) 83725 - 83731 2015.10

Combining novel device architecture and NIR dye towards the fabrication of transparent conductive oxide-less tandem dye sensitized solar cells Reviewed

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 2015.09

Investigation of metal xanthates as latent curing catalysts for epoxy resin via formation of in-situ metal sulfides Reviewed

Tarun Chand Vagvala, Shyam Sudhir Pandey, Yuhei Ogomi, Tingly Ma, Shuzi Hayase

INORGANICA CHIMICA ACTA 435 292 - 298 2015.08

First principles study on the electronic and optical properties of B-site ordered double perovskite Sr 2 MMoO 6 (M= Mg, Ca, and Zn) Reviewed

Shuai Zhao, Chunfeng Lan, Jie Ma, Shyam S Pandey, Shuzi Hayase, Tingli Ma

Solid State Communications 213-214 19 - 23 2015.04

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 2015.04

Nonisothermal curing kinetics of epoxy resin composite utilizing Ga (III) xanthate as a latent catalyst Reviewed

Tarun Chand Vagvala*, Gaurav Kapil, Shyam S. Pandey, Yuhei Ogomi and Shuzi Hayase*

Journal of Applied Polymer Science 132 ( 26 ) 42149-1 - 42149-7 2015.03

Dye-sensitized solar cells based on axially ligated phosphorus-phthalocyanine dyes Reviewed

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 2015.03

Complete Photodynamics of the Efficient YD2-o-C8 Based Solar Cell Reviewed

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 2014.11

A COMBINED THEORETICAL AND EXPERIMENTAL APPROACHES TOWARDS DESGNING NIR DYES FOR DYE-SENSITIZED SOLAR CELLS Reviewed

YOSHIHIRO YAMAGUCHI, SHYAM S. PANDEY, NAOTAKA FUJIKAWA, YUHEI OGOMI, SHUZI HAYASE

Journal of Engineering Science and Technology 9 53 - 66 2014.10

A combined theoretical and experimental approaches towards designing nir dyes for dye-sensitised solar cells Reviewed

9 ( Spec. Issue on Applied Engineering and Sciences (SAES2013), October 2014 ) 51 - 65 2014.10

Titanium wire engineering and its effect on the performance of coil type cylindrical dye sensitized solar cells Reviewed

Gaurav Kapil, Shyam S Pandey, Yuhei Ogomi, Tingli Ma, Shuzi Hayase

Organic Electronics 15 3399 - 3405 2014.09

Tandem dye-sensitized solar cells with a back-contact bottom electrode without a transparent conductive oxide layer Reviewed

AK Baranwal, T Shiki, Y Ogomi, SS Pandey, T Ma, S Hayase

RSC Advances 4 47735 - 47742 2014.09

Transparent conductive oxide-less back contact dye-sensitized solar cells using cobalt electrolyte Reviewed

Md. Zaman Molla, Norihiro Mizukoshi, Hiroaki Furukawa, Yuhei Ogomi, Shyam S. Pandey, Tingli Ma and Shuzi Hayase

Progress in Photovoltaic Research and Applications 2014.06

Graphene Oxide Based Biosensor for Food Toxin detection Reviewed

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 2014.06

Template Assisted Electrochemical Growth of Polypyrrole Nanotubes for Development of High Sensitivity Glucose Biosensor Reviewed

Pragya Agar Palod, Shyam S. Pandey, Shuzi Hayase and Vipul Singh

Applied Biochemistry and Biotechnology 174 1059 - 1072 2014.06

Far-Red Sensitizing Octatrifluorobutoxy Phosphorous Triazatetrabenzo-corrole: Synthesis, Spectral Characterization and Aggregation Studies Reviewed

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 2014.06

Gallium (III) xanthate as a novel thermal latent curing agent for epoxy resin composite Reviewed

Tarun Chand Vagvala, SHYAM S PANDEY, Yuhei Ogomi, Shuji Hayase

RSC Advances 4 24658 - 24661 2014.05

All solid perovskite solar cells with HOCO-R-NH3I anchor group inserted between porous TiO2 and perovskite Reviewed

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 2014.05

Fabrication and characterization of coil type transparent conductive oxide less cylindrical dye-sensitized solar cells Reviewed

Gaurav Kapil, Jin Ohara, Yuhei Ogomi, SHYAM S PANDEY, Tingli Ma and Shuzi Hayase

RSC Advances 4 22959 - 22963 2014.05

Spectroscopy and Dynamics of YD2-o-C8 in Solution and Interacting with Alumina Nanoparticles Electrode Reviewed

Maria Rosaria di Nunzio, Boiko Cohen, Shyam S. Pandey, Shuzi Hayase, Giovanni Piani, and Abderrazzak Douhal

Journal of Physical Chemistry C 118 11365 - 11376 2014.05

Transparent conductive oxide-less back contact dye-sensitized solar cells using Zinc porphyrin dye employing cobalt complex redox shuttle Reviewed

1538 - 1542 2014.01

Flexible transparent conductive oxide-less cylinder dyesensitized solar cells Reviewed

2013.11

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 Reviewed

2 ( 1 ) 2013.11

Effect of extended π-conjugation on photovoltaic performance of dye sensitized solar cells based on unsymmetrical squaraine dyes Reviewed

69 ( 12 ) 2633 - 2639 2013.03

Effect of extended p-conjugation on photovoltaic performance of dye-sensitized solar cells based on unsymmetrical squaraine dyes Reviewed

Shyam S. Pandey, Rie Watanabe, Naotaka Fujikawa, Gururaj M. Shivashimpi, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

Tetrahedron 69 2633 - 2639 2013.01

Electrophoretic deposition onto an insulator for thin film preparation toward electronic device fabrication Reviewed

Shougo Miyajima, Shuichi Nagamatsu, Shyam S. Pandey, Shuzi Hayase, Keiichi Kaneto and Wataru Takashima

Applied Physics Letters 101 193305-1 - 193305-4. 2012.11

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 Reviewed

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 2012.11

Dye-Sensitized Solar Cells based on Novel Far-red Sensitizing Unsymmetrical Squaraine Dye containing Pyrroloquinoline Moiety Reviewed

Shyam S. Pandey, Naotaka Fujikawa, Rie Watanabe, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

Japanese Journal of Applied Physics 51 ( 10 ) 10NE12-1 - 10NE12-5 2012.10

Differences in Dye-Sensitized Photovoltaic Behaviours between SnO2 and TiO2 Electrodes Reviewed

Kengo Sadamasu, Yuhei Ogomi, Shyam S. Pandey and Shuzi Hayase

Japanese Journal of Applied Physics 51 ( 10 ) 10NE05-1 - 10NE05-5 2012.10

Relating the Photodynamics of Squaraine-Based Dye-Sensitized Solar Cells to the Molecular Structure of the Sensitizers and to the Presence of Additives Reviewed

G. de Miguel, M. Marchena, B. Cohen, S. S. Pandey, S. Hayase and A. Douhal

Journal of Physical Chemistry-C 116 ( 42 ) 22157 - 22168 2012.10

Dye sensitized solar cells based on novel far red sensitizing unsymmetrical squaraine dye containing pyrroloquinoline moiety Reviewed

51 ( 10 PART 2 ) 2012.10

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 2012.10

Solution processable thin film organic photovoltaic cells based on far red sensitive2 soluble squaraine dye Reviewed

Shyam S. Pandey, Takafumi Mizuno, Sandeep K. Das, Yuhei Ogomi and Shuzi Hayase.

Thin Solid Films 522 401 - 406 2012.08

Novel unsymmetrical squaraine dye bearing cyanoacrylic acid anchoring group and its photosensitization behaviour Reviewed

Gururaj M. Shivashimpi, Shyam S. Pandey, Rie Watanabe, Naotaka Fujikawa, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

Tetrahedron Letters 53 ( 40 ) 5437 - 5440 2012.07

Femto- to millisecond photophysical characterization of indole-based squaraines adsorbed on TiO <inf>2</inf> nanoparticle thin films Reviewed

116 ( 22 ) 12137 - 12148 2012.06

Femto to Millisecond Photophysical Characterization of Indole-based Squaraines Adsorbed on TiO2 Nanoparticle Thin Films. Reviewed

de Miguel, Gustavo; Marchena, Maria Jose; Ziolek, Marcin; Pandey, Shyam; Hayase, Shuzi; Douhal, Abderrazzak

Journal of Physical Chemistry-C; 116 ( 22 ) 12137 - 12148 2012.05

Flexible Transparent Conductive Oxide-less Flat and Cylinder Dye-Sensitized Solar Cells Reviewed

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 2012.05

Photophysics of H-and J-aggregates of Indole based squaraines in solid state. Reviewed

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 2012.04

Multiple electron injection dynamics in linearly linked two dye-co-sensitized nanocrystalline metal oxide electrode for dye sensitized solar cells;; Reviewed

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 2012.01

Transparent conductive oxide less flexible dye-sensitized solar cells with flat and cylinder shapes Reviewed

1435 ( January ) 51 - 54 2012.01

Femto to millisecond observations of indole-based squaraines molecules photodynamics in Solution Reviewed

G. de Miguel, M. Marchena, M. Ziolek, M, Zitnan, S. S. Pandey, S Hayase and A. Douhal

Physical Chemistry and Chemical Physics 2011.12

Multiple electron injection from dyes to titania layer for high efficiency-dye-sensitized solar cells Reviewed

001187 - 001191 2011.12

Transparent Conductive Oxide-less thee-dimentional cylindrical dye-sensitized solar cell fabricated with flexible metal mesh electrode Reviewed

Jun Usagawa, Shyam S. Pandey, Yuhei Ogomi, Sho Noguchi, Yoshihiro Yamaguchi and Shuzi Hayase

Progress in Photovoltaics Research and Applications 2011.11

Aiming at high efficiency dye-sensitized solar cells - From the view point of photoconversion interface Reviewed

79 ( 10 ) 761 - 764 2011.10

Fine tuning the structure of unsymmetrical squaraine dyes towards the development of efficient dye sensitized solar cells Reviewed

Shyam S. Pandey, Rie Watanabe, Naotaka Fujikawa, Yuhei Ogomi, Yoshihiro Yamaguchi and Shuzi Hayase

SPIE Proceeding 8111 811116-1 - 811116-9 2011.09

Investigating the Role of Dye Dipole on Open Circuit Voltage in Solid-State Dye-Sensitized Solar Cells Reviewed

Shyam S Pandey, Kyung-Young Lee, Azwar Hayat, Yuhei Ogomi, and Shuzi Hayase

Japanese Journal of Applied Physics 50 ( 6 ) 06GF08-1 - 06GF08-4 2011.06

Transparent conductive oxideless tandem dye-sensitized solar cells consisting of light-splitting structures Reviewed

Jun Usagawa,Masaki Kaya,Yuhei Ogomi,Shyam S. Pandey,and Shuzi Hayase

Journal of Photonics for Energy 1 ( 1 ) 011110 - 1 2011.03

Hybrid Dye-Sensitized Solar Cells Consisting of Double Titania Layers for Harvesting Light with Wide Range of Wavelengths Reviewed

Kengo Sadamasu,Takafumi Inoue,Yuhei Ogomi,Shyam S. Pandey,and Shuzi Hayase

Applied Physics Express 4 ( 2 ) 022301 - 1 2011.01

TCO-less 3D-DYE-sensitized solar cells consisting of charge separation sheet and direction to high efficiency cells by using TCO-less structure Reviewed

518 - 522 2010.12

Electron Injection from Linearly Linked Two Dye Molecules to Metal Oxide Nanoparticles for Dye Sensitized Solar Cells Covering Wavelength Range from 400-950 nm Reviewed

Byung-wook Park,Takafumi Inoue,Yuhei Ogomi,Akari Miyamoto,Shinsuke Fujita,Shyam S. Pandey and Shuzi Hayase

Applied Physics Express 4 ( 1 ) 012301 - 1 2010.12

Tandem dye-sensitized solar cells consisting of floating electrode in one cell Reviewed

216 ( 2-3 ) 104 - 109 2010.12

TCO-less 3D dye-sensitized solar cells consisting of charge separation sheet -tandem, hybrid, cylinder and fiber cells- Reviewed

171 - 175 2010.12

Solvation Effect on the Ion Exchange in Polypyrrole Film doped with Sulfonated Polyaniline Reviewed

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 2010.08

Probing Mechanism of Dye Double Layer Formation from Dye Cocktail Solution for Dye Sensitized Solar Cells Reviewed

Yuhei Ogomi,Shyam S. Pandey,Shunta Kimura and Shuzi Hayase

Thin Solid Fims 519 1087 - 1092 2010.08

Tandem Dye-Sensitized Solar Cells Consisting of Nanoporous Titania Sheet Reviewed

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 2010.08

Alkyl and Fluoro-alkyl Substituted Squaraine Dyes: A Prospective Approach Towards Development of Novel NIR Sensitizers Reviewed

Shyam S. Pandey,Takafumi Inoue,Naotaka Fujikawa,Yoshihiro Yamaguchi and Shuzi Hayase

Thin Solid Films 519 1066 - 1071 2010.08

Tandem Dye Sensitized Solar Cells Consisting of Floating Electrode in One Cell Reviewed

Kenshiro Uzaki,Shyam S. Pandey,and Shuzi Hayase

Journal of Photochemistry and Photobiology A: Chemistry 216 ( 1 ) 104 - 109 2010.08

Substituent Effect in Direct Ring Functionalized Squaraine Dyes on Near Infra-Red Sensitization of NanocrystallineTiO2 for Molecular Photovoltaics Reviewed

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 2010.07

Synthesis and characterization of squaric acid based NIR dyes for their application towards dye sensitized solar cells Reviewed

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 2010.04

Tandem Dye Sensitized Solar Cells Consisting of Floating Electrode Supported by Non-Conductive Glass Mesh Reviewed

Kenshiro Uzaki,Shyam S. Pandey,Yuhei Ogomi and Shuzi Hayase

Advances in Science and Technology 74 157 - 163 2010.04

Influence of nature of surface dipoles on observed photovoltage in dye-sensitized solar cells as probed by surface potential measurements Reviewed

Shyam S. Pandey,Shohei Sakaguchi,Yoshiro Yamaguchi,Shuzi Hayase

Organic Electronics 11 ( 3 ) 419 - 426 2009.11

Role of morphology on Photoluminescence quenching and depletion width formed at the interface of Aluminum and Poly(3-Alkylthiophene) Reviewed

Vipul Singh,Shyam S Pandey,Wataru Takashima,and Keiichi Kaneto

Japanese Journal of Applied Physics 41 ( 6 ) 061503 - 1 2009.06

Tandem Dye-Sensitized Solar Cells Fabricated on Glass Rod without Transparent Conductive Layers Reviewed

Jun Usagawa,Shyam S. Pandey,Shuzi Hayase,Mitsuru Kono,and Yoshihiro Yamaguchi

Applied Physics Express 2 ( 6 ) 062203 - 1 2009.06

Transparent Conductive Oxide layer-less dye-sensitized solar Cells consisting of floating electrode with gradient TiOx layer Reviewed

Applied Physics Letters 94 093301 - 093301 2009.04

Preparation of Double Dye-Layer Structure of Dye-Sensitized Solar Cells from Cocktail Solutions for Harvesting Light in Wide Range of Wavelengths Reviewed

Japanese Journal of Applied Physics 48 ( 2 ) 020213 - 020213 2009.04

Optical and Electrical Characterization of Poly(3-hexylthiophene-2,5-diyl) Interface with Al and LiF Reviewed

Japanese Journal of Applied Physics 47 ( 2B ) 1251 - 1255 2008.04

Characterization of Depletion Layer using Photoluminescence Technique Reviewed

Applied Physics Express 1 ( 2 ) 021801 - 021801 2008.04

A comparative study of Al and LiF:Al interfaces with Poly (3-Hexylthiophene) using bias dependent photoluminescence technique Reviewed

Organic Electronics 9 ( 5 ) 790 - 796 2008.04

Solvation contribution on the ion exchange in polypyrrole films doped with sulfonated polyaniline Reviewed

Physical Chemistry and Chemical Physics 2008.04

Evidence of Photoluminescence Quenching in Poly (3-hexylthiophene-2,5-diyl)due to injected charge carriers Reviewed

Synthetic Metals 158 ( 7 ) 283 - 286 2008.04

Probing TiO2/dye Interface in Dye Sensitized Solar Cells using Surface Potential Measurement Reviewed

Applied Physics Express 1 ( 10 ) 105001 - 105001 2008.04

Role of morphology on Photoluminescence quenching and depletion width formed at the interface of Aluminum and Poly(3-Alkylthiophene) Reviewed

Japanese Journal of Applied Physics 2008.04

Synthetic and Characterization of Dendritic Poly(L-lysine) containing Porphyrin-Fullerene Moieties Reviewed

Synthetic Metals 157 311 - 317 2007.04

Simultaneous co-immobilization of enzyme and a redox mediator in poly pyrrole film for the fabrication of an amperometric phenol biosensor Reviewed

Current Applied Physics 5 ( 2 ) 184 - 188 2005.04

Patternable bi-ionic actuator: an example of new functionality of actuation, folding and unfolding of electrochemical spring Reviewed

Sensors and Actuators B: Chemical 110 ( 1 ) 120 - 124 2005.04

Electrochemomechanical Deformation in Conducting Co-polymers containing Pyrrole and Anisidine Moieties Reviewed

Reactive and Functional Polymers 58 103 - 110 2004.04

Development of Amperometric Biosensor Based on Redox Mediator doped Polypyrrole Films Reviewed

Journal of Applied Polymer Science 93 927 - 933 2004.04

Enhanced Electrochemomechanical Deformation of Polyaniline Film by Optimization of pH and Electrolyte Concentration Reviewed

Trans. Material Research Society 229 ( 3 ) 771 - 774 2004.04

Conserved Electrochemomechanical Activities of Polypyrrole Films in Complex Buffer Media Reviewed

Sensors & Actuators B: Chemical 102 142 - 147 2004.04

Improved Cathodic Expansions of Electrochemomechanical behavior of Polypyrrole Films Electrodeposited from Aerosol OT Emulsion Reviewed

Chemistry Letters 33 996 - 996 2004.04

Electrochemically Generated Deformation of Polyaniline Film Plasticized with DI-2-butoxy, 2-ethoxy ester of Sulfosuccinic acid Reviewed

Sensors & Actuators B: Chemical 99 601 - 607 2004.04

Electrochemomechanical Deformation studies of Hexacyanoferrate Ion doped Polypyrrole Film Reviewed

Thin Solid Films 467 227 - 230 2004.04

Enhanced Electrochemomechanical Activities of Polyaninile Films Towards High pH Region: Contribution of Donnan Effect Reviewed

Electrochimica Acta 49 4239 - 4244 2004.04

Investigation of bi-ionic Contribution for enhancement of Bending Actuation in Polypyrrole Film Reviewed

Sensors & Actuators B: (Chemical) 89 48 - 52 2003.04

Effect of Disorder on the Magnetic States in Pol(3-hexylthiophene) Reviewed

Synthetic Metals 135-136 343 - 343 2003.04

Bi-Ionic Actuators by Polypyrrole Films Reviewed

Synthetic Metals 135-136 61 - 61 2003.04

Enhanced Electrochemomechanical Behaviors of Polyanilne Films by Chloride Concentrations Reviewed

Chemistry Letters 32 ( 11 ) 990 - 990 2003.04

Photovoltaic Properties in Poly(3-alkylthiophene) based Heterojunction Cells Reviewed

Current Applied Physics 3 ( 2-3 ) 107 - 113 2003.04

Proposal of Novel Actuators Using Conducting Polymer Laminates Reviewed

Synthetic Metals 135-136 135 - 135 2003.04

Structure-Property Correlation: Electrochemomechanical Deformation in Polypyrrole Films Reviewed

Thin Solid Films 438-439 206 - 211 2003.04

Immobilization of Glucose Oxidase on to Langmuir Blodgett Films Poly(3-hexylthiophene) Reviewed

Current Applied Physics 3 ( 2-3 ) 275 - 279 2003.04

Effect of Film Morphology on the Actuation Behavior in Polypyrrole Films Reviewed

Synthetic Metals 135-136 59 - 59 2003.04

Cyclic-voltammetry and electrochemomechanical deformation of freestanding polypyrrole film in diluted media Reviewed

Thin Solid Films 438-439 339 - 345 2003.04

Temperature Dependence of Rectification and Photovoltaic Effects in Regioregular Poly(3-alkylthiophene) films at the Schottky Junction of Al Electrode Reviewed

Current Applied Physics 3 ( 2-3 ) 321 - 324 2003.04

Electrochemomechanical Deformation of Polypyrrole Film in Complex Buffer Media Reviewed

IPMM CD Book 2003.04

Cyclic Step-voltammetric Analysis of Cation-driven and Anion-driven Actuuation in Polypyrrole Films Reviewed

Japanese Journal of Applied Physics 41 7532 - 7536 2002.04

Photocarrier Transport Modulated by Film Morphology in Regioregular Poly(3-hexyl thiophene) Reviewed

Thin Solid Films 393 334 - 342 2001.04

Photocarrier Generation in Regioregular Poly(3-alkylthiophene) Photovoltaic Cells Reviewed

Synthetic Metals 121 1565 - 1565 2001.04

Photocarrier Mobility in Poly(2-methoxyaniline) Reviewed

Journal of Applied Polymer Science 79 ( 8 ) 1506 - 1512 2001.04

Photovoltaic Cell using High Mobility Poly(alkylthiophene)s and TiO2 Reviewed

Synthetic Metals 121 1537 - 1537 2001.04

Poly(3-Butylthiophene):Conjugated Polymer with Record High TOF Mobility Reviewed

Synthetic Metals 121 1561 - 1561 2001.04

Dispersivity of Carrier Transport related with Molecular Arrangement in Regioregular Poly(3-alkylthiophene) Reviewed

Synthetic Metals 119 563 - 563 2001.04

Photocarrier Transport in Non-Uniform Field Based on Schottky Cell for the Time-of-Flight Measurements Poly(3-alkyl thiophene) Films Reviewed

Japanese Journal of Applied Physics 40 ( 8 ) 4933 - 4937 2001.04

Effect of Regioregularity on carrier transport in Poly(alkylthiophene) films with various alkyl chain lengths Reviewed

Current Applied PhysICW 1 ( 1 ) 90 - 97 2001.04

Photocarrier Transport in Regioregular Poly(3-octadecylthiophene) Reviewed

Japanese Journal of Applied Physics 40 5350 - 5356 2001.04

Photocarrier Transport in Processable Poly(3-alktlthiophenes) Reviewed

Synthetic Metals 121 1563 - 1563 2001.04

Morphology Effect on Photocarrier Transport in Regioregular Poly(3-alkylthiphene) Films

IEICE-OME ED-2001 41 - 47 2001.04

Thermal Analysis of Chemically Synthesized Polyemeraldine Base Reviewed

Journal of Applied Polymer Science 75 ( 1 ) 145 - 149 2000.04

Mechanism of Photocarrier Generation and Transport in Poly(3-alkylthiophene) films Reviewed

Japanese Journal of Applied Physics 39 6309 - 6315 2000.04

Effect of Synthetic Impurities on Photocarrier Transport in Poly(3-hexylthiophene) Reviewed

IEICE Transactions on Electronics E-83 ( 7 ) 1088 - 1093 2000.04

Role of Processing Solvents in Photocarrier Transport of Polyaniline Reviewed

Japqnese Journal of Applied Physics 39 ( 7A ) 4445 - 4450 2000.04

Regioregularity Vs Regiorandomness: Effect on Photocarrier Transport in Poly(3-hexyl thiophene) Reviewed

Japanese Journal of Applied Physics 39 94 - 97 2000.04

Covalent Immobilization of Glucose Oxidase to Poly(o-aminobenzoic acid) for application to Glucose Biosensor Reviewed

Journal of Applied Polymer Science 78 ( 3 ) 662 - 667 2000.04

Time of Flight Mobility of Poly(3-alkylthiophenes) Reviewed

W. Takashima,S. S. Pandey,M. Rikukawa,and K. Kaneto

Technical report of IEICE OME99 ( 231 ) 29 - 34 2000.04

Photocarrier Transport Phenomena in Polythiophene derivatives Reviewed

S. Nagamatsu,Shyam S. Pandey,W. Takashima,K. Kaneto

Pusan-Kyeongnam/Kyushu-Seibu joint International Symposium 14 - 14 1999.11

Carrier Mobility of Conducting Polymers Reviewed

W. Takashima,S. Nagamatsu,W. Y. Lim,K. Endo,M. Kaneko,S. S. Pandey and K. Kaneto

Pusan-Kyeongnam/Kyushu-Seibu joint International Symposium 1999.11

Effect of Regiospecificity on Photocarrier Mobility in Poly(3-hexylthiophene Reviewed

Shyam S. Pandey,S. Nagamatsu,M. Kaneko,W. Takashima,M. Rikukawa and K. Kaneto

Pusan-Kyeongnam/Kyushu-Seibu joint International Symposium 1999.11

a Reviewed

M. Kaneko,Shyam S. Pandey,K. Takayama,S. Nagamatsu,Lim W. Y,W. Takashima,K. Kaneto and M. Rikukawa

1999.11

Time-of-Flight Photocarrier Mobility in Langmuir-Blodgett Films of Regioregular Poly(3-hexyl thiophene Reviewed

Japanese Journal of Applied Physics 38 6768 - 6771 1999.04

Photocarrier Mobility in Regioregular Poly(3-hexylthiophene) Studied by Time-of-Flight Method Reviewed

Japaneswe Journal of Applied Physics 38 1188 - 1190 1999.04

TOF Mobility in Poly(3-hexylthiophene)

IEICE-OME-99 17 29 - 29 1999.04

Dielectric relaxation in thin conducting polyaniline films Reviewed

Polymer 39 ( 15 ) 3399 - 3404 1998.04

Electrical Properties of Metal(Indium)/PolyanilineSchottky devices Reviewed

Journal of Applied Polymer Science 65 2745 - 2745 1997.04

A.C. Conductivity of Polyemeraldine Base Reviewed

Journal of Physics Condensed Matter 6 8913 - 8922 1994.04

Muon studies of conducting polymers Reviewed

Synthetic Metals 55 677 - 677 1993.04

Optical and Electrical Characteristics of the Electrodeposited Polypyrrole Films Reviewed

Journal of Applied Polymer Science 50 ( 3 ) 411 - 411 1993.04

Photocarrier mobility in processable polyaniline Reviewed

Journal of Applied Physics 74 2109 - 2109 1993.04

Synthesis and Characterization of Poly(aniline-co-orthoanisidine): A processable conducting polymer Reviewed

Macromolecules 26 3190 - 3190 1993.04

Some recent studies on Metal/polyaniline Schottky devices; Reviewed

Journal of Applied Polymer Science 44 ( 5 ) 911 - 911 1992.04

Vacuum Deposited Metal/Polyaniline Schottky Diode Reviewed

Applied Physics Letters 61 1219 - 1219 1992.04

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<PANDEY Shyam sudhir>

Papers - PANDEY Shyam sudhir