記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

DOI： 10.1016/j.molliq.2024.125822

DOI： 10.1016/j.molliq.2024.125822

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.mtelec.2024.100112

DOI： 10.1016/j.mtelec.2024.100112

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

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

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

DOI： 10.3390/colorants3030014

DOI： 10.3390/colorants3030014

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

DOI： 10.1016/j.jtice.2024.105639

DOI： 10.1016/j.jtice.2024.105639

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.envres.2024.119435

DOI： 10.1016/j.envres.2024.119435

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.molstruc.2024.138994

DOI： 10.1016/j.molstruc.2024.138994

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.optmat.2024.115535

DOI： 10.1016/j.optmat.2024.115535

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

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

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

DOI： 10.3390/mi15060677

DOI： 10.3390/mi15060677

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

Design and synthesis of pro-active nano metal oxides.

•
Advanced and cost-effective process for water treatment.

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

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

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

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

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

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

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

Kyutacar

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1109/LSENS.2023.3347760

DOI： 10.1109/LSENS.2023.3347760

Kyutacar

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

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

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

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

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

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

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

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

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

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

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

Kyutacar

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

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

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

Kyutacar

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

Kyutacar

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

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

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

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

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

Kyutacar

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

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

Kyutacar

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

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

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

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

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

Kyutacar

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

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

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

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

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

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.47836/pjst.31.3.12

DOI： 10.47836/pjst.31.3.12

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.molliq.2023.121754

DOI： 10.1016/j.molliq.2023.121754

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

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

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

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

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

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

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

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

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

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

Kyutacar

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

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

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

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

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

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

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

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

Kyutacar

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

DOI： 10.23919/AM-FPD54920.2022.9851297

DOI： 10.23919/AM-FPD54920.2022.9851297

その他リンク： http://www.amfpd.jp/

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

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

DOI： 10.23919/AM-FPD54920.2022.9851340

DOI： 10.23919/AM-FPD54920.2022.9851340

その他リンク： http://www.amfpd.jp/

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

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

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

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

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

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

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

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

DOI： 10.35848/1347-4065/ac28e8

Scopus

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

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

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

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

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

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

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

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

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

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

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

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

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

DOI： 10.1088/1742-6596/2070/1/012040

Scopus

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

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

DOI： 10.1016/j.solener.2021.08.014

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

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

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

DOI： 10.23919/AM-FPD52126.2021.9499214

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsami.1c09671

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.tsf.2021.138814

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1002/pssr.202100185

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.synthmet.2021.116797

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

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

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

DOI： 10.1016/j.matpr.2021.03.468

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

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

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

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

DOI： 10.1117/12.2584521

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.optmat.2021.110886

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

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

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

DOI： 10.1007/s11705-021-2117-z

Scopus

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

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

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsami.0c14874

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.ijleo.2020.165595

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1038/s41598-020-77022-0

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1117/1.JPE.10.045501

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsaelm.0c00437

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.solener.2020.08.011

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1002/pssa.202000144

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1007/s10854-020-04092-1

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

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

DOI： 10.23919/AM-FPD49417.2020.9224472

Kyutacar

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.synthmet.2020.116378

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.jphotochem.2020.112467

Kyutacar

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.orgel.2020.105687

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsami.9b23345

Kyutacar

その他リンク： https://pubs.acs.org/doi/abs/10.1021/acsami.9b23345

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.7567/1347-4065/ab48b9

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.3390/ma12213643

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

Kyutacar

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1063/1.5109083

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1039/C9TC04397G

Kyutacar

その他リンク： https://pubs.rsc.org/no/content/articlelanding/2019/tc/c9tc04397g/unauth#!divAbstract

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

Kyutacar

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.solmat.2019.03.013

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.carbon.2019.02.086

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsami.8b22044

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.orgel.2019.02.011

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1080/16583655.2018.1516028

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

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.orgel.2018.10.043

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsomega.8b01240

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.solener.2018.09.026

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsaem.8b00653

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.rser.2018.06.031

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acssuschemeng.8b01550

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1063/1.5000566

Kyutacar

その他リンク： https://aip.scitation.org/

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.orgel.2018.02.012

Kyutacar

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

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

DOI： 10.1002/admi.201700875

Kyutacar

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

記述言語：英語   掲載種別：研究論文（学術雑誌）

We have developed a new method to obtain Ribbon-shaped floating films via dynamic casting of floating-film and transfer method (dynamic-FTM). Dynamic-FTM is a unique method to prepare oriented thin-film of conjugated polymers (CPs) which is quick and easy. This method has several advantages as compared to the other conventional casting procedure to prepare oriented CP films. In the conventional dynamic FTM appearance of large scale circular orientation poses difficulty not only for practical applications but also hinders the detailed analysis of the orientation mechanism. In this present work, pros and cons of this newly proposed ribbon-shaped floating-film have been discussed in detail from those of the conventional floating-film prepared by dynamic-FTM.

DOI： 10.1088/1742-6596/924/1/012014

Kyutacar

その他リンク： http://iopscience.iop.org/article/10.1088/1742-6596/924/1/012014/meta

記述言語：英語   掲載種別：研究論文（学術雑誌）

A series of far-red sensitive symmetrical squaraine dyes bearing direct–COOH
functionalized indole ring were synthesized, characterized and subjected to photophysical
investigations. These symmetrical squaraine dyes were then subjected to investigate their
interaction with bovine serum albumin (BSA) in Phosphate buffer solutions. All the squaraine
dyes under investigation exhibit intense and sharp optical absorption mainly in the far-red
wavelength region from 550 nm-700 nm having very high molar extinction coefficients from
1.3× 10 5 dm 3. mol− 1. cm− 1. A very small Stokes shift of 10-17 nm indicates the rigid
conformational structure of squaraine chromophore. Interaction of these dyes with BSA
leads to not only enhanced emission intensity but also bathochromically shifted absorption
maximum due to formation of dye-BSA conjugate. These dyes bind strongly with BSA

DOI： 10.1088/1742-6596/924/1/012006

Kyutacar

その他リンク： http://iopscience.iop.org/article/10.1088/1742-6596/924/1/012006/meta

記述言語：英語   掲載種別：研究論文（学術雑誌）

A far-red sensitizing dye SQ-75 has been employed as a model sensitizer with Co
(bpy) 2+/3+ redox electrolytes to fabricate dye-sensitized solar cells (DSSCs) and optimize
the various device parameters which influence the overall photoconversion efficiency (PCE).
It has been found that the optimization of the TiO 2 thickness, surface treatment with TiCl 4,
and an optimum amount of the chenodeoxycholic acid (CDCA) as coadsorber are necessary
to attain the overall improved PCE. TiCl 4 surface treatment on both FTO and TiO 2 has been
found to outperform as compared to their untreated counterparts owing to the suppression of
the charge recombination. DSSCs with an optimized TiO 2 thickness of 6 μm and CDCA
concentration of 4 mM have exhibited best performance due to enhanced photon harvesting
and reduced dye aggregation, respectively.

DOI： 10.1088/1742-6596/924/1/012001

Kyutacar

その他リンク： http://iopscience.iop.org/article/10.1088/1742-6596/924/1/012001/meta

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Combined theoretical and experimental approaches were implemented to design model far-red sensitive unsymmetrical squaraine dyes in order to estimate the minimum energy barrier required for dye regeneration. Our logical molecular design indicated that it is possible to have a fine control on the energetics within 0.2 eV only by the judicious selection of substituents and alkyl chain length keeping the main π-molecular framework the same. The utilization of the LSDA functional under TD-DFT calculations offered an effective and economical computational method for the reliable prediction of the energetics as well as the absorption maximum of the sensitizers. Among the designed dyes under investigation, SQ-75 exhibited the best photovoltaic performance, having a short-circuit current density of 10.92 mA cm−2, open circuit voltage of 0.57 V and a fill factor of 0.67, leading to a photoconversion efficiency of 4.25% despite having photon harvesting mainly in the far-red region. The best photon harvesting by SQ-75, even with an energy difference of only 0.12 eV between the energy of its highest occupied molecular orbital and redox energy level I−/I3− electrolyte, corroborates the possibility for dye regeneration with such a small driving force.

DOI： 10.1039/C7TA06990A

Kyutacar

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.bmcl.2017.07.057

Kyutacar

その他リンク： https://www.sciencedirect.com/science/article/pii/S0960894X17307643

記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Elsevier B.V. In the present study, device geometry having top contact bottom gated poly(2,5-bis(3-tetradecylthiophen-2yl)thieno(3,2-b)thiophene) (PBTTT) based polymer thin film transistor (PTFT) is reported to measure the changes in electrical responses with the exposure to various concentrations of ammonia vapor at room temperature. PTFT is preferred over other electronic devices due to its multi-parameter characteristics to explore gas sensing capabilities. A facile floating–film transfer method (FTM) is used to prepare an active layer of PTFT by forming optimized thin layer of PBTTT film having a thickness of ∼25 nm. Exposure to various concentrations of ammonia vapor, device parameters like I/O characteristics, mobility, threshold voltage, and trap density are found to change significantly. As PTFT is exposed to 100 ppm ammonia vapor a 70% reduction in mobility is observed whereas threshold voltage shifted to more negative from −17.62 V to −23.64 V. Better sensing capabilities with a detection limit of 0.33 ppm, fast response and recovery of exposed ammonia vapor are observed, when PTFT is operated in sub-threshold regime rather than the cut-off or saturated regime. All the electrical characterizations for the sensing purpose are carried out in ambient but in a closed chamber. Device shows enormous potential for ammonia sensing for real and environmental applications.

DOI： 10.1016/j.snb.2017.02.063

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.jpcc.7b04019

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.jpcc.7b03416

記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Dynamic casting of floating-film and transferring method for preparing oriented multilayer films of conjugated polymers is reported. This method is based on dynamic casting of a floating-film on liquid substrate to obtain oriented thin-film followed by its transfer on a desired solid substrate. The uniqueness in this method lies in the isolation of casting and coating procedures of oriented films, which enables us to fabricate the oriented multilayer with minimum interlayer interference. It provides a key-technology to build up the organic multi-layered architecture while preserving oriented morphologies. Several types of multilayer films have been prepared and investigated in detail in terms of their film characteristics. The layer-by-layer coating of oriented films demonstrated by this method is found to be a unique feature which overcomes cumbersome procedures in the conventional orientation methods. The coating procedure demonstrated in this study provides a facile methodology to construct anisotropic architectures.

DOI： 10.1016/j.synthmet.2017.02.018

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Elsevier B.V. Considering the advantages of floating film transfer method (FTM), we have investigated the optical and electronic characteristics of PBTTT-C14 thin-films prepared by the static and the dynamic casting on liquid substrate. It has been demonstrated that judicious selection of solvents during FTM switches the casting mode from the static casting (S-FTM) using high boiling point solvent to the dynamic casting (D-FTM) from low boiling point solvent. Although both of the methods provide the edge-on oriented structure of PBTTT-C14 by XRD, the structural and the optical analyses reveal relatively extended π-conjugation length in parallel D-FTM film as compared to that of S-FTM. A high field-effect mobility (μ) of 0.11 cm 2 /V.s was exhibited by OFETs fabricated by parallel D-FTM film even without any high temperature post-annealing up to the liquid crystalline phase transition. This observed value of μ for parallel D-FTM is 4.7 and 12.8 times higher than the isotropic S-FTM and the perpendicular D-FTM films, respectively.

DOI： 10.1016/j.orgel.2017.01.031

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Copyright © 2017 American Scientific Publishers All rights reserved. Orientation in conjugated polymers is a unique phenomenon by the virtue of their one dimensionality leading to semiconductor performances in organic electronic devices. A unique, cost-effective and highly efficient method for the fabrication of oriented thin film consisted of non-regiocontrolled poly(3-hexylthiophene) (NR-P3HT) using dynamic floating-film transfer method (dynamic-FTM) has been investigated. Orientation of NR-P3HT by dynamic-FTM has been quantitatively measured as the optical anisotropy represented by dichroic ratio (DR). Amongst several factors like concentration of polymer solution, temperature and viscosity of liquid-substrate along with post-annealing temperature, viscosity of liquid-substrate plays a crucial role in controlling the molecular orientation. A judicious control and optimization of various underlying factors affecting the molecular orientation led to relatively high DR of 9.3 even in NR-P3HT films cast by dynamic-FTM.

DOI： 10.1166/jnn.2017.12816

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85009971833&origin=inward

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.jpcc.7b00760

その他リンク： http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.7b00760

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.solmat.2015.10.033

Kyutacar

その他リンク： http://www.sciencedirect.com/science/article/pii/S0927024815005449

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.dyepig.2017.01.015

Kyutacar

その他リンク： http://www.sciencedirect.com/science/article/pii/S0143720816307975

記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 Society of Photo-Optical Instrumentation Engineers (SPIE). A flat titanium sheet with microholes (FTS-MH) has been utilized to fabricate transparent conductive oxide-less dye-sensitized solar cells (TCO-less DSSCs) in back contact device architecture. Utilization of FTS-MH to fabricate a TCO-less photoanode offers several advantages in terms of simplicity and ease of fabrication as compared with the TCO-less DSSCs structure reported previously. Hydrogen peroxide (H 2 O 2 ) surface treatments on FTS-MH have shown important factors to enhance the photoanode properties. H 2 O 2 surface treatment is able to change the surface morphology of FTS-MH, and the created anatase titanium dioxide (TiO 2 ) nanostructures increase the surface contact between the FTS-MH and the coated mesoporous TiO 2 . Electrochemical impedance investigations reveled that improvements of the FTS-MH/TiO 2 and TiO 2 /dye/electrolyte interface led to hampered charge recombination resulting in enhancement of both short-circuit current density and open-circuit voltage, respectively. Even after removal of both TCO layers, our complete TCO-less DSSCs exhibited a power conversion efficiency of 7.25% under simulated solar irradiation.

DOI： 10.1117/1.JPE.7.015501

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Copyright © 2017 American Scientific Publishers. All rights reserved. Thin Ti-metal protected stainless steel metal mesh coated with mesoporous TiO 2 as flexible photoanode has been used to fabricate back contact transparent conductive oxide-less dye-sensitized solar cells. TiO 2 nanoparticle having a particle size of 15-20 nm sensitized with dye cocktail of two indoline dyes D-205 and D-131 were first utilized owing to their complementary light harvesting properties. Short-circuit photocurrent density (J sc ) for the dye cocktail combination of D-205 and D-131 (1:1) was found to be increased due to the increased photon harvesting in the 400-500 nm mainly associated with the contribution from D-131 dye. In addition, the electron recombination was suppressed when dye cocktail was employed as confirmed by the dark current measurement leading to higher open-circuit voltage (V oc ). The enhanced J sc accompanied with increased V oc resulted in to an improved efficiency of 3.59% for this cocktail combination. To enhance the efficiency even further, we have utilized TiO 2 nanoparticle having a larger particle size of 30 nm facilitating the mass transport of the bulky [Co(bpy) 3 ] 3+/2+ redox species. In order to enhance the photon harvesting window TiO 2 nanoparticles were sensitized with porphyrin dye (YD2-o-C8) along with different dye cocktail combinations with another complementary dye (Y123). Utilization of a dye cocktail of YD2-o-C8 and Y123 (4:1) led to improved photoconversion efficiency of 5.25% under simulated solar irradiation.

DOI： 10.1166/jnn.2017.13746

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2016 Elsevier B.V. Dynamic casting of conjugated polymer films on liquid-substrate is a unique method which provides thin floating-film and can be easily transferred on a desired substrate by stamping. The important feature in this procedure is associated with the formation of thin polymeric film during compression and solidification controlled by viscous drag of liquid substrate and solvent evaporation of the polymer, respectively. Lyotropic liquid-crystalline (LC) characteristics of conjugated polymer possibly assist to orient the polymer chain in one direction. It is found that this method produce highly oriented thin films (dichroic ratio >  5) of thiophene-based conjugated polymers such as PBTTT-C14, PQT-C12 and non-regiocontrolled poly(3-hexylthiophene) NR-P3HT. On the other hand, weak orientation intensity in regioregular poly(3-hexylthiophene) RR-P3HT was found. The mechanism for this diverse orientation in thiophene-based conjugated polymers is discussed in correlation with the backbone chemical structure and lyotropic LC phase transition during the floating-film formation.

DOI： 10.1016/j.tsf.2016.11.015

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84997830850&origin=inward

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/acs.chemmater.6b02315

その他リンク： http://pubs.acs.org/doi/abs/10.1021/acs.chemmater.6b02315

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.orgel.2016.08.003

その他リンク： http://www.sciencedirect.com/science/article/pii/S156611991630341X

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1166/jnn.2016.12324

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1166/jnn.2016.12316

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012002

Kyutacar

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012003

Kyutacar

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012005

Kyutacar

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1088/1742-6596/704/1/012012

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1166/jnn.2016.12275

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）

Copyright © 2016 American Scientific Publishers. All rights reserved. Model squaraine dyes having sharp and narrow absorptions mainly in the far-red wavelength region has been logically designed, synthesized and used for their application as sensitizer in the dye-sensitized solar cells (DSSC). In order to have fine control on energetics, dyes having same mother core and alkyl chain length varying only in molecular symmetry and position of substituent were designed. It has been found that even keeping all other structural factor constant, only positional variation of substituent leads to not only in the variation of energetics by 0.1 eV but affects the photovoltaic characteristics also. Optimum concentration of dye de-aggregating agent was found to be 100 times with respect to the sensitizing dye concentration. Amongst dyes utilized in this work best performance was obtained for unsymmetrical dye SQ-40 giving a photoconversion efficiency of 4.01% under simulated solar irradiation at global AM 1.5.

DOI： 10.1166/jnn.2016.12304

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c6ra04894c

Scopus

その他リンク： http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra04894c/unauth#!divAbstract

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/C6RA05581H

その他リンク： http://pubs.rsc.org/is/content/articlelanding/2016/ra/c6ra05581h/unauth#!divAbstract

記述言語：英語   掲載種別：研究論文（学術雑誌）

© The Royal Society of Chemistry 2016. The perovskite-type oxide ABO 3 with mixed ionic and electronic conductivity (MIEC) is a promising candidate for electrode materials of the intermediate-temperature solid oxide fuel cells (IT-SOFCs). The strontium molybdate SrMoO 3 shows high electrical conductivity but low oxygen ionic conductivity due to the stoichiometric features of oxygen. To enhance the oxygen ions diffusion rate, B-site Mo 4+ cation was partially substituted by trivalent transition metals (TM) to generate the oxygen-deficient double perovskite Sr 2 BMoO 6-δ . In this study, we present the theoretical investigation of the oxygen vacancy properties of Sr 2 CrMoO 6 (SCM) using density functional theory (DFT) with on-site Coulomb potential U for the Cr 3d electrons. The oxygen vacancy formation and migration were investigated for the B-site-ordered SCM, as well as the SCM with Cr/Mo antisite defects (ADs). The oxygen ion migration was optimized by the climbing image nudged elastic band (CINEB) method to identify the minimum energy pathway. The B-site Cr/Mo ADs allow various TM-O bond types in the double perovskite SCM. The calculated formation energy and migration barrier suggests that the B-site Cr/Mo ADs are favorable to enhance the oxygen ionic conductivity of the SCM. These results elucidate the influence of B-site Cr and Mo cations on the oxygen vacancy formation and migration in the double perovskite SCM, which can be useful for investigating Cr-doped SrMoO 3 as an IT-SOFCs anode.

DOI： 10.1039/c6ra05581h

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© The Royal Society of Chemistry 2016. Molybdenum-based double perovskites have been extensively studied as electrode materials in solid oxide fuel cells (SOFCs) due to their mixed ionic/electronic conductivity (MIEC) characteristics. Since the ionic conductivity in perovskite crystals arises primarily from oxygen ion diffusion via a vacancy-hopping mechanism, both the formation energy of the oxygen vacancy and the migration energy barrier play an essential role in the MIEC performance. In this work, we present a detailed first-principles investigation on the stoichiometric and oxygen-deficient structures of double perovskites, Sr 2 BMoO 6 (B = Mg, Co and Ni), using the density functional theory (DFT) method plus Hubbard U for Co and Ni. The electronic ground states of the oxygen-stoichiometric cells exhibited apparent eigenvalue gaps which are consistent with the measured insulating features. The oxygen-deficient structures were studied by removing a neutral oxygen atom according to SOFC working conditions, and the minimum energy path (MEP) of oxygen ion migration was optimized using the nudged elastic band (NEB) method which produced the theoretical migration energy barriers at the DFT+U level. The vacant oxygen sites released electrons to the adjacent cation d states, coupled with the delocalization characteristics of the Mo 4d state, which led eventually to the transition from an insulator to the electronic conductivity of the oxygen-deficient crystals. The electronic structure analysis suggested that the outer shell electrons of Mg, Co and Ni significantly affected the energies of oxygen vacancy formation and migration. Our results elucidate the effect of B-site substitution elements on the electronic properties and MIEC characteristics which provides theoretical support for the enhancement of the MIEC properties for these Mo-based double perovskites.

DOI： 10.1039/c6ra02297a

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/zaac.201500639

Scopus

その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/zaac.201500639/full

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.7567/APEX.8.125501

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CiNii Article

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c5ra11992h

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.7567/APEX.8.102301

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CiNii Article

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.ica.2015.07.020

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.ssc.2015.04.012

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.electacta.2015.04.071

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その他リンク： http://www.sciencedirect.com/science/article/pii/S0013468615009639

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/app.42149

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その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/app.42149/full

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.7567/APEX.8.047001

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CiNii Article

その他リンク： http://iopscience.iop.org/1882-0786/8/4/047001

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp510761z

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記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

© School of Engineering, Taylor’s University. Sensitizing dyes especially having capability of sharp light absorption in the near infrared region play a pivotal role towards enhancing the photovoltaic efficiency of dye-sensitised solar cells. Effort has been directed towards the optimization of suitable calculation parameters for the theoretical calculations to assist the design of novel sensitizers for the dye-sensitised solar cells using Gaussian program package. Suitability of the calculation parameters as well as calculated results using the same model, unsymmetrical squaraine dye (SQ-1) was designed, synthesized and used for their characterisation and photovoltaic applications. Calculation results were performed in both ground and excited states of this molecule and indicate that B3LYP and B3PW91 are quite suitable hybrid functional for theoretical calculation using DFT and 6-311G basis set. Electronic absorption maximum for SQ-A in ethanol solution exhibits the peak at 650 nm which was found to be only 47 nm (0.04 eV) higher as compared to the calculated value (603 nm) using PCM solvent model under TD-DFT.

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.orgel.2014.09.023

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c4ra07539k

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/pip.2526

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1007/s12010-014-0965-4

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1007/s12010-014-0988-x

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.jphotochem.2014.05.011

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c4ra03151b

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp412627n

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c4ra02999b

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp503449q

Scopus

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2014 IEEE. A transparent conductive oxide-less (TCO-less) dye-sensitized solar cell (DSSC) consisting of back-contacted stainless steel metal mesh electrode has been fabricated. In this work, [Co(bpy) 3 ] 3+/2+ complex based redox electrolyte and porphyrin dye as sensitizer were utilized. Owing to relatively deeper redox energy level for cobalt based electrolytes as compared to I 3 - /I - redox system, possibility of obtaining high open-circuit voltage was explored. Employing a thin film of Ti on the metal mesh as the charge recombination blocking layer resulted in enhanced photoconversion efficiency. TCO-less DSSC in combination with cobalt electrolyte gave the power conversion efficiency of 4.89% under simulated solar irradiation.

DOI： 10.1109/PVSC.2014.6925209

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Dye sensitized solar cells which does not need transparent conductive oxide layered glass (TCO-less DSCs) are reviewed. Especially, flexible cylinder TCO-less DSCs with 5.1% efficiency is focused on. © OSA 2013.

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

High performance SnO 2 -based bottom electrodes are necessary for tandem dye-sensitized solar cells (DSSCs) harvesting infrared (IR) lights. Sensitizing dyes based on macrocyclic ligands are one of the candidates among the IR dyes. However, it is difficult to introduce anchoring groups such as carboxylic acid at the right position of macrocyclic rings where electron injection occurs. It was proved that axially anchored phthalocyanines (model compounds) bonded to SnO 2 nanoparticle surfaces with short metal-O-metal linkage inject electrons from dyes to SnO 2 layers spatially, because themacrocyclic rings are very close to SnO 2 surfaces. TiO 2 based DSSCs did not show photovoltaic properties because of very fast charge recombination between injected electrons and oxidized dyes which were measured by a transient absorption spectroscopy technique. In the case of SnO 2 -based DSSC, the charge recombination was slower than that of the TiO 2 -based DSSCs, which enabled the collection of electrons. Since this anchoring system can be prepared easily, it is a good strategy for use in the design of near-IR absorbing dye. © 2012 The Electrochemical Society.

DOI： 10.1149/2.014301jss

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Aiming toward the far-red to near infra-red (NIR) photon harvesting, three new unsymmetrical squaraine dyes bearing direct ring carboxy functionalized indole as an anchoring moiety with varying donor groups with extended π-conjugation have been successfully synthesized and utilized for dye sensitized solar cell fabrication. Under simulated solar irradiation, dye SQ-8 gave a photoconversion efficiency of 3.3% mainly harvesting photons in the far-red region between 500 and 700 nm. By extending the π-conjugation of the donor moieties in the novel unsymmetrical squaraine dyes, it was possible to extend the light absorption from far-red to NIR wavelength region. In spite of good light absorption up to 900 nm and energetic matching, dye SQ-16 was found to exhibit the decreased photon harvesting, which was explained by the enhanced dye aggregation along with its difficulty in facile electron injection as indicated from electronic absorption spectroscopic and DFT calculation results, respectively. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2013.01.036

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1063/1.4766126

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/JJAP.51.10NE05

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CiNii Article

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp306125y

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記述言語：英語   掲載種別：研究論文（学術雑誌）

A novel far-red sensitive and direct aromatic ring carboxy functionalized unsymmetrical squaraine dye based on pyrroloquinoline moiety has been synthesized for the application as sensitizer of dye sensitized solar cells. This dye bearing the characteristics of both of indole and quinoline moieties exhibits the photon harvesting up to 820 nm. The enhancement in the photon harvesting window by the pyrroloquinoline based squaraine dye was attributed to the presence of increased π-conjugation in its pyrroloquinoline donor part. This pyrroloquinoline bearing unsymmetrical squaraine dye exhibits a short circuit current density of 9.88 mA/cm2, an open circuit voltage of 0.57 V and fill factor of 0.59 leading to the external power conversion efficiency of 3.33% under simulated solar irradiation of 100mW/cm2 at AM 1.5 condition. © 2012 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.51.10NE12

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記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2012.08.043

Scopus

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tetlet.2012.07.125

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）

In this paper, we address femto- to millisecond transient absorption studies of TiO 2 nanoparticle (NP) thin films sensitized with four squaraine (SQ) molecules, with and without a deaggregating agent, chenodeoxycholic acid (CDCA). On the femto- to picosecond time scale, we determined the presence of three transient species by using singular value decomposition (SVD) analysis, i.e., S 1 of the SQ monomers, S 1 of the SQ H-aggregates, and the SQ radical cation formed after the electron injection. Both monomers and H-aggregates are proven to inject electrons to the TiO 2 conduction band, being 5 times faster in the monomers (e.g., k ei mon = 5.1 × 10 11 s -1 and k ei H-agg = 1.1 × 10 11 s -1 for SQ 41). Besides, the undesired singlet-singlet annihilation is an active process in these samples, constituting the drain of a high percentage of the absorbed photons. The coadsorption of CDCA on the TiO 2 NP avoids the formation of H-aggregates, and therefore, only two transient species are present in these samples: S 1 of the monomer and the SQ radical cation with k ei mon = 6.7 × 10 11 s -1 for SQ 41. On the microsecond scale, we only observed the transient feature of the radical cation of the SQ that permits one to study its recombination dynamics. Similar lifetimes (94-150 μs) of the four SQ radial cations are obtained when only monomers are present in the sample. In the absence of CDCA, the presence of H-aggregates contributes to shorten the lifetime of the radical cation (e.g., from 110 to 45 μs in the case of SQ 41). This fact can be explained by considering a stronger electronic coupling of H-aggregates/TiO 2 surface with respect to the monomers. These results explore the photodynamics of this family of SQs adsorbed on TiO 2 NP in a very large time window and will enable a better understanding of the influence of aggregates in the kinetics of these SQs used as sensitizers in DSSCs. © 2012 American Chemical Society.

DOI： 10.1021/jp302928f

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記述言語：英語   掲載種別：研究論文（学術雑誌）

その他リンク： https://pubs.acs.org/journal/jpccck

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1117/1.JPE.2.021011

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1021/jp210281z

Scopus

その他リンク： https://pubs.acs.org/journal/jpccck

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c2cp23522f

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2012 Materials Research Society. Transparent conductive oxide less flexible dye-sensitized solar cells (TCO-less DSC) with flat and cylinder shapes are reported. The cell consists of a plastic cover, a flexible titania/dye sheet back contacted with a metal mesh sheet, a gel electrolyte sheet, and Pt layer on a Ti sheet. How to increase the efficiency were discussed. We concluded that making a titania/dye layer on a metal mesh sheet thinner and using a thinner electrolyte layer were effective for increasing the efficiency. A flat TCO-less DSC with 6.1 % efficiency and a cylindrical TCO-less DSC with 5.1 % efficiency are reported.

DOI： 10.1557/opl.2012.1695

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1039/c1cp22864a

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その他リンク： http://pubs.rsc.org/en/content/articlelanding/2012/cp/c1cp22864a

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

We report two kinds of dye-sensitized solar cells where multiple electron injection mechanism is used. One is multiple electron injection consisting of linearly linked two dye molecules. Tin(IV) 2,11,20,29-tetra-tert-butyl-2,3- naphthalocyanine (NcSn) was adsorbed on a SnO 2 surface by a Sn(p)-O-Sn(n) linkage, where Sn(p) and Sn(n) stand for a Sn atom on a Sn nanoparticle surface and that at the center of NcSn, respectively. Cis-diisothiocyanato- bis(2,2′-bipyridyl-4,4′-dicarboxylato) ruthenium(II) bis(tetrabutylammonium), known as N719, was bonded to NcSn by a-Sn(n)-O-CO-linkage. The incident photon to photocurrent efficiency (IPCE) curve of the cell (DD-cell) suggested that electrons are injected from both N719 and NcSn to SnO 2 nanoparticles. The mechanism was supported by transient absorption spectra studies. The other is multiple electron injection from double titania layer (top and bottom layers). The top and bottom electrodes were stained with different dyes having different λ max. A top layer fabricated on a glass was mechanically pressed with a bottom layer fabricated on a glass cloth to fabricate an anode. The glass cloth acts as a supporter of a porous titania layer as well as a holder of electrolyte. The incident photon to current efficiency (IPCE) curve had two peaks corresponding to those of the two dyes, which demonstrates that electrons are collected from both the top and bottom layers. © 2011 IEEE.

DOI： 10.1109/PVSC.2011.6186168

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1002/pip.1223

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Researches aiming at high efficiency-dye-sensitized solar cells (DSC) are reviewed from the view point of photoconversion interfaces. Developments of dyes converting photons to electrons in near infrared regions are essential for increasing short circuit current (Jsc). Hybrid cells consisting of double dye structures and double titania layer structures are proposed. Leak currents at photoconversion interfaces decrease open circuit voltage (Voc) and fill factor (FF). Therefore, strategies for decreasing leak currents are essential, especially for all-solid DSCs and IVLf free DSCs. Structures of these interfaces are discussed in terms of surface passivation, self-organization, dye structures, interactions between dyes and I3 - in titania nanopores. Fundamental studies for tandem cells are also reported.

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

USA   Sandiego, LA   2011年08月21日  -  2011年08月26日

DOI： 10.1117/12.893354

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その他リンク： http://dx.doi.org/10.1117/12.893354

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/JJAP.50.06GF08

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CiNii Article

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1117/1.3555458

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/APEX.4.022301

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CiNii Article

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Three dimensional transparent conductive oxide-less dye-sensitized solar cells (3D-TCO-less DSCs) consisting of a flexible porous titania sheet are reported. The flexible titania sheet is composed of a dye stained porous titania layer and a mesh sheet acting as the backbone. Flexible TCO-less DSCs, tandem DSCs, TCO-less cylinder DSCs and TCO-Iess cubic DSCs are fabricated and their fundamental photovoltaic performances are reported. © 2010 IEEE.

DOI： 10.1109/PVSC.2010.5616802

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/APEX.4.012301

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CiNii Article

記述言語：英語   掲載種別：研究論文（学術雑誌）

Tandem dye-sensitized solar cells (Cell TAN) consisting of a floating electrode (bottom cell) and a TiO 2 electrode prepared on a F-doped SnO 2 glass (top cell) are reported. The floating electrode is a flexible and self-standing composite film consisting of a porous titania/dye layer supported by a mesh electrode. The floating electrode was inserted between the TiO 2 electrode and the counter electrode in a conventional single dye-sensitized solar cell to fabricate the Cell TAN. Therefore, the Cell TAN is completely different from previously reported tandem cells where two cells are merely accumulated and connected to each other. The Incident Photon to Current Conversion Efficiency (IPCE) curve for the Cell TAN had two peaks corresponding to those of the two single cells. The open circuit voltage (V oc ) of the Cell TAN (0.88 V) was higher than that of the corresponding single cell (0.6-0.66 V). These two results strongly demonstrated that the Cell TAN has a potential for tandem cells. © 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jphotochem.2010.07.025

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Three dimensional transparent conductive oxide-less dye-sensitized solar cells (3D-TCO-less DSCs) consisting of a flexible porous titania sheet are reported. The flexible titania sheet is composed of a dye stained porous titania layer and a mesh sheet acting as the backbone. Flexible TCO-less DSCs, tandem DSCs, TCO-less cylinder DSCs and TCO-less cubic DSCs are fabricated and their fundamental photovoltaic performances are reported. ©2010 IEEE.

DOI： 10.1109/NANO.2010.5698067

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2010.08.050

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2010.08.049

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1143/JJAP.49.082301

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CiNii Article

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.tsf.2010.08.045

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記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.jphotochem.2010.07.010

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記述言語：英語   掲載種別：研究論文（学術雑誌）

DOI： 10.1016/j.jphotochem.2010.04.015

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記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

主要雑誌

DOI： 10.1016/j.orgel.2009.11.021

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

主要雑誌

記述言語：英語   掲載種別：研究論文（学術雑誌）

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記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

2003年04月  -  2003年04月

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

Seoul (South Korea)   Chinju   1999年11月02日  -  1999年11月03日

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

South Korea   Chinju   1999年11月02日  -  1999年11月03日

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

South Korea   Chinju   1999年11月02日  -  1999年11月03日

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

South Korea   Chinju   1999年11月02日  -  1999年11月03日

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

1993年04月  -  1993年04月

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

1993年04月  -  1993年04月

記述言語：英語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（学術雑誌）

開催期間： 2023年03月01日   記述言語：日本語   開催地： Kitakyushu International Conference Center, Kokura   国名：日本国  

Yuki Kurokawa Received the Best Presentation Award for this Research Presented

開催期間： 2024年03月11日 - 2024年03月12日   記述言語：英語   開催地：AKS University, Satna, MP, India   国名：インド  

開催期間： 2024年01月30日 - 2024年01月31日   記述言語：英語   開催地：PGSR, Coimbatore,Tamilnadu, India   国名：インド  

開催期間： 2024年01月30日 - 2024年01月31日   記述言語：英語   開催地：PGSR, Coimbatore,Tamilnadu, India   国名：インド  

開催期間： 2024年01月30日 - 2024年01月31日   記述言語：英語   開催地：PGSR, Coimbatore,Tamilnadu, India   国名：インド  

開催期間： 2024年01月30日 - 2024年01月31日   記述言語：英語   開催地：PGSR, Coimbatore,Tamilnadu, India   国名：インド  

開催期間： 2024年01月30日 - 2024年01月31日   記述言語：英語   開催地：PGSR, Coimbatore,Tamilnadu, India   国名：インド  

開催期間： 2023年12月06日 - 2023年12月08日   記述言語：英語   開催地：Toki Messe Convention Center, Niigata, Japan   国名：日本国  

開催期間： 2023年11月29日 - 2023年11月30日   記述言語：英語   開催地：Indian Institute of Technology, Guwahati, India   国名：インド  

開催期間： 2023年11月20日 - 2023年11月21日   記述言語：英語   開催地：UPM Malaysia   国名：マレーシア  

開催期間： 2023年11月20日 - 2023年11月21日   記述言語：英語   開催地：UPM, Malaysia   国名：マレーシア  

開催期間： 2023年11月20日 - 2023年11月21日   記述言語：英語   開催地：UPM, Malaysia   国名：マレーシア  

開催期間： 2023年11月20日 - 2023年11月21日   記述言語：英語   開催地：UPM, Malaysia   国名：マレーシア  

開催期間： 2023年11月20日 - 2023年11月21日   記述言語：英語   開催地：UPM, Malaysia   国名：マレーシア  

開催期間： 2023年11月14日 - 2023年11月16日   記述言語：日本語   開催地：Yokohama, Japan   国名：日本国  

開催期間： 2023年11月14日 - 2023年11月16日   記述言語：英語   開催地：Yokohama, Japan   国名：日本国  

開催期間： 2023年11月14日 - 2023年11月16日   記述言語：日本語   開催地：Yokohama, Japan   国名：日本国  

開催期間： 2023年10月30日 - 2023年11月04日   記述言語：英語   開催地：Ashoka Hotel, New Delhi, India   国名：インド  

開催期間： 2023年10月11日 - 2023年10月13日   記述言語：英語   開催地：I-site Namba, Osaka Metropolitan Univ., Osaka, Japan   国名：日本国  

開催期間： 2023年09月19日 - 2023年09月23日   記述言語：英語   開催地：Kumamoto Castle Hall Kumamoto   国名：日本国  

開催期間： 2023年09月19日 - 2023年09月23日   記述言語：英語   開催地：Kumamoto Castle Hall Kumamoto   国名：日本国  

開催期間： 2023年09月19日 - 2023年09月23日   記述言語：英語   開催地：Kumamoto Castle Hall Kumamoto   国名：日本国  

開催期間： 2023年09月19日 - 2023年09月23日   記述言語：英語   開催地：Kumamoto Castle Hall Kumamoto   国名：日本国  

開催期間： 2023年09月12日 - 2023年09月13日   記述言語：英語   開催地：UPM, Malaysia   国名：マレーシア  

This was a Keynote Presentation made by Shyam S. Pandey

開催期間： 2023年09月11日 - 2023年09月12日   記述言語：英語   開催地：Ito Campus, Kyushu University,   国名：日本国  

開催期間： 2023年09月11日 - 2023年09月12日   記述言語：英語   開催地：Ito Campus, Kyushu University,   国名：日本国  

開催期間： 2023年09月05日 - 2023年09月08日   記述言語：英語   開催地：Nagoya Congress Center, Nagoya Japan   国名：日本国  

開催期間： 2023年07月04日 - 2023年07月07日   記述言語：英語   開催地：Ryukoku University Avanti Kyoto Hall Kyoto, Japan   国名：日本国  

開催期間： 2023年07月01日   記述言語：英語   開催地： Kitakyushu International Conference Center, Kokura   国名：日本国  

開催期間： 2023年07月01日   記述言語：英語   開催地： Kitakyushu International Conference Center, Kokura   国名：日本国  

開催期間： 2023年07月01日   記述言語：英語   開催地： Kitakyushu International Conference Center, Kokura   国名：日本国  

開催期間： 2023年07月01日   記述言語：日本語   開催地： Kitakyushu International Conference Center, Kokura   国名：日本国  

開催期間： 2023年07月01日   記述言語：英語   開催地：Kitakyushu International Conference Center, Kokura   国名：日本国  

開催期間： 2023年06月05日 - 2023年06月08日   記述言語：英語   開催地：Busan, South Korea   国名：北朝鮮＝朝鮮民主主義人民共和国  

開催期間： 2023年06月05日 - 2023年06月08日   記述言語：英語   開催地：Busan, South Korea   国名：北朝鮮＝朝鮮民主主義人民共和国  

開催期間： 2023年05月26日 - 2023年05月27日   記述言語：英語   開催地：Tokyo Institute of Technology Ookayama, Tokyo   国名：日本国  

開催期間： 2023年04月26日 - 2023年06月30日   記述言語：英語   開催地：Suntec, Singapore   国名：シンガポール共和国  

開催期間： 2023年03月17日 - 2023年03月18日   記述言語：英語   開催地：PDEU, Gujrat, India   国名：インド  

開催期間： 2023年03月01日   記述言語：日本語   開催地：Hitotsubashi Hall, Tokyo, Japan   国名：日本国  

開催期間： 2023年02月02日 - 2023年02月04日   記述言語：英語   開催地：IGNTU, Amarkantak, MP, India   国名：インド  

開催期間： 2022年12月16日 - 2022年12月18日   記述言語：英語   開催地：NIT-Silchar, Assam India   国名：インド  

開催期間： 2022年12月12日 - 2022年12月14日   記述言語：英語   開催地：Tokyo Institute of Technology   国名：日本国  

開催期間： 2022年12月12日 - 2022年12月14日   記述言語：英語   開催地：Tokyo Institute of Technology   国名：日本国  

開催期間： 2022年12月12日 - 2022年12月14日   記述言語：英語   開催地：Tokyo Institute of Technology   国名：日本国