研究者詳細 - 永松　秀一

その他リンク： https://doi.org/10.1038/s41598-020-77022-0

Long-Term Air-Stable n-Channel Organic Thin-Film Transistors Using 2, 5-Difluoro-1, 4-phenylene-bis {2-[4-(trifluoromethyl) phenyl] acrylonitrile} 査読有り国際誌

Shuichi Nagamatsu, Shinya Oku, Kouji Kuramoto, Tetsuji Moriguchi, Wataru Takashima, Tatsuo Okauchi, Shuzi Hayase

Shuichi Nagamatsu, Shinya Oku, Kouji Kuramoto, Tetsuji Moriguchi, Wataru Takashima, Tatsuo Okauchi, Shuzi Hayase 6 ( 6 ) 3847 - 3852 2014年03月

A Steady Operation of n-Type Organic Thin-Film Transistors with Cyano-Substituted Distyrylbenzene Derivative 査読有り国際誌

Nagamatsu Shuichi, Moriguchi Tetsuji, Nagase Toshiya, OKU Shinya, KURAMOTO Kouji, TAKASHIMA Wataru, OKAUCHI Tatsuo, MIZOGUCHI Katsuhiro, HAYASE Shuji, KANETO Keiichi

Applied physics express ( Japan Society of Applied Physics ) 2 ( 10 ) "101502 - 1"-"101502-3" 2009年10月

Crystal Structure of Friction-Transferred Poly(2,5-dioctyloxy-1,4-phenylenevinylene) 査読有り国際誌

Shuichi Nagamatsu,Masahiro Misaki,Masayuki Chikamatsu,Tatsumi Kimura,Yuji Yoshida,Reiko Azumi,Nobutaka Tanigaki,Kiyoshi Yase

The Journal of Physical Chemistry B 111 ( 17 ) 4349 - 4354 2007年05月

Polymer field-effect transistors by a drawing method 査読有り国際誌

Shuichi Nagamatsu,Wataru Takashima,Keiichi Kaneto,Yuji Yoshida,Nobutaka Tanigaki,Kiyoshi Yase

Applied Physics Letters 84 ( 23 ) 4608 - 4610 2004年06月

Backbones Arrangement in "Friction-Transferred" Regioregular Poly(3-alkylthiophene)s 査読有り国際誌

Shuichi Nagamatsu,Wataru Takashima,Keiichi Kaneto,Yuji Yoshida,Nobutaka Tanigaki,Kiyoshi Yase,Kazuhiko Omote

Macromolecules 36 ( 14 ) 5252 - 5257 2003年07月

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

Nagao T., Yasukawa M., Pandey S.S., Misaki M., Nagamatsu S.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 63 ( 11 ) 2024年11月

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）

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

DOI： 10.35848/1347-4065/ad8ed2

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

Sharma S., Gaurav K.V., Nagamatsu S., Pandey S.S.

Polymers 16 ( 5 ) 2024年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

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： 10.3390/polym16050710

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

Sharma S., Pandey M., Nagamatsu S., Tanaka H., Takashima K., Nakamura M., Pandey S.S.

ACS Applied Materials and Interfaces 2024年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsami.4c03111

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

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

Physica Status Solidi (A) Applications and Materials Science 2023年08月

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

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

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

記述言語：英語掲載種別：研究論文（学術雑誌）

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

DOI： 10.1016/j.cej.2023.143932

その他リンク： https://doi.org/10.1016/j.cej.2023.143932

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

Rai H., Vivek Gaurav K., Pradhan S., Desu M., Sharma S., Nagamatsu S., Pandey S.S.

Physica Status Solidi (A) Applications and Materials Science 2023年06月

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： 10.1002/pssa.202300236

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

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

Materials Today Electronics 4 2023年06月

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： 10.1016/j.mtelec.2023.100043

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

Desu M., Sharma S., Cheng K.H., Wang Y.H., Nagamatsu S., Chen J.C., Pandey S.S.

Organic Electronics 113 2023年02月

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/Vs.

DOI： 10.1016/j.orgel.2022.106691

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Fabrication and Characterization of Oriented P3HT/CdS Hybrid Thin Films Prepared by Friction Transfer for Organic Photovoltaics 査読有り

Kurokawa Y., Pradhan S., Kato T., Nagamatsu S., Pandey S.S.

30th International Workshop on Active-Matrix Flatpanel Displays and Devices: TFT Technologies and FPD Materials, AM-FPD 2023 - Proceedings 169 - 172 2023年01月

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）

Simple, low-cost one-step fabrication donor-Acceptor hybrid thin films are highly desired for the practical realization of low-cost organic solar cells. In this work, oriented and hybrid thin films of P3HT/CdS were successfully fabricated by a solvent-free friction transfer (FT) method utilizing Cadmium xanthate [Cd(Xt)2] as CdS precursor and regioregular P3HT in a single step. Complete conversion of [Cd(Xt)2] to CdS with optical band gap of 2.53 eV after thermal annealing at 200 °C was confirmed by absorption spectral investigation. Polarized absorption spectral results revealed that FT-processed hybrid thin films of P3HT/CdS were oriented and extent of molecular orientation was enhanced after the thermal annealing at 200 °C. Highly oriented hybrid thin films with dichroic ratio of 6.95 was prepared under the optimum fabrication conditions such stage speed, stage temperature and applied load of 1200 mm/min, 85°C and 2.4 kg, respectively.

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

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

Proceedings of AM-FPD 2022 29th International Workshop on Active-Matrix Flatpanel Displays and Devices (AM-FPD) 116 - 119 2022年07月

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）

Aligned thin films with controlled molecular orientation are highly desired for high performance organic electronic devices. A crystalline conjugated copolymer DPP- TTT has been utilized to prepare large area and oriented thin films by the floating film transfer method (FTM). Amongst the various factors controlling the orientation under FTM, relative viscosities of polymer solution and orthogonal liquid substrates have been demonstrated to playa pivotal role not only in controlling the magnitude but also the directionality of the molecular orientation. It was revealed that utilization of the polymer solution and orthogonal liquid substrates with varying viscosities exhibited a reversal of orientation direction, when the viscosity of the polymer solution was higher than that of the orthogonal liquid substrate.

DOI： 10.23919/AM-FPD54920.2022.9851340

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

Yuki Kurokawa, Ajendra K. Vats, Shuichi Nagamatsu, Shyam S. Pandey

Proceedings of AM-FPD 2022 29th International Workshop on Active-Matrix Flatpanel Displays and Devices (AM-FPD) 2022年07月

令和3年度日本表面真空学会九州支部セミナー開催報告

永松秀一

表面と真空 ( 公益社団法人日本表面真空学会 ) 65 ( 6 ) 288 - 288 2022年06月

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

Sharma S., Vats A.K., Pandey M., Nagamatsu S., Chen J.C., Pandey S.S.

ACS Applied Polymer Materials 4 ( 11 ) 8315 - 8323 2022年01月

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： 10.1021/acsapm.2c01283

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Fast-Coating Process Based on Elongated Rodlike Preaggregate for Highly Oriented Thin Film of Donor-Acceptor π-Conjugated Polymer 査読有り国際誌

Minowa Y., Yabuuchi Y., Nagano S., Nagamatsu S., Fujii A., Ozaki M.

ACS Applied Materials and Interfaces 2022年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

A fast meniscus-guided coating for ultrahighly oriented thin films of a typical donor-acceptor π-conjugated polymer, poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno[3,2-b]thiophene)](PDPP-DTT) was realized. A coating speed higher than 100 mm/s, which was regarded as a Landau-Levich regime, was applicable. The 2D order parameter (S2) of the thin films changed by selecting the solvent and adjusting the initial concentration of the solution, and the large elongated rodlike preaggregates formed particularly in chlorobenzene contributed to the high orientation in the solid film state, resulting in the highest value of S2 = 0.87. Focused on the PDPP-DTT preaggregate formation in the solution, the SAXS analysis was carried out to investigate the shape and size of the preaggregates. The mechanism of the molecular orientation was discussed by taking the preaggregates and the solution flow under the coating process into account.

DOI： 10.1021/acsami.2c13516

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Dynamics of Preaggregation and Film Formation of Donor–Acceptor π-Conjugated Polymers 査読有り国際誌

Yuta YabuuchiYuta Yabuuchi Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan More by Yuta Yabuuchi , Yu Minowa, Shuichi Nagamatsu, Akihiko Fujii, and Masanori Ozaki

ACS Materials Letters 4 ( 2 ) 205 - 211 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

It is important to understand the film formation mechanism of π-conjugated polymers to realize their high-performance electronic devices. In this study, the dynamics of the preaggregate, which affects the conformation and alignment of a typical donor-acceptor (D-A) π-conjugated polymer during film formation, was investigated by two approaches based on a small-angle X-ray scattering (SAXS) method. SAXS analysis of a highly concentrated solution, assuming the state before becoming the solid-state thin film, provided insight into the aggregation phenomena of the D-A π-conjugated polymer during the film formation process. In solution, the small rod-like structure of the polymer seems to form a large preaggregate, the shape of which almost coincided with that of the aggregate in the solid-state thin film. Besides, in situ grading incident SAXS (in situ GISAXS) analysis in the actual film formation process from the solution state revealed a microstructural change of the aggregate over time.

DOI： 10.1021/acsmaterialslett.1c00734

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Oriented Thin Films of Insoluble Polythiophene Prepared by the Friction Transfer Technique 査読有り国際誌

Nobutaka Tanigaki, Chikayo Takechi, Shuichi Nagamatsu, Toshiko Mizokuro, Yuji Yoshida

Polymers ( MDPI ) 13 ( 15 ) 2393 2021年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

A thin film of unsubstituted polythiophene (PT), an insoluble conjugated polymer, with molecular chains uniaxially oriented in plane was prepared by the friction transfer method. The structure of highly oriented thin films of PT was investigated using grazing-incidence X-ray diffraction (GIXD), ultraviolet-visible (UV-vis) spectroscopy, and infrared (IR) spectroscopy. The polarized UV-vis and IR spectra and GIXD measurements showed the PT molecular chains were well aligned in parallel to the friction direction. The GIXD studies clarified that the polymer backbones were aligned with very narrow distribution, such that the half-width was about 4 degrees. The degree of orientation of the PT friction-transferred film was higher compared with those of regioregular poly(3-alkylthiophene)s. Moreover, the GIXD results show a preferred orientation where the a-axis is perpendicular to the substrate plane.

DOI： 10.3390/polym13152393

その他リンク： https://doi.org/10.3390/polym13152393

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

Yuki Kurokawa, Shuichi Nagamatsu, Shyam S. Pandey

2021 28th International Workshop on Active-Matrix Flatpanel Displays and Devices (AM-FPD) 2021年06月

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

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

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

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

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

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

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

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

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Molecular orientation and anisotropic charge transport in the large area thin films of regioregular Poly(3-alkylthiophenes) fabricated by ribbon-shaped FTM 査読有り国際誌

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

Organic Electronics 81 2020年03月

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

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Investigation and Control of Charge Transport Anisotropy in Highly Oriented Friction-Transferred Polythiophene Thin Films 査読有り国際誌

Nikita KumariNikita Kumari Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu 8080Nikita Kumari, Manish Pandey, Shuichi Nagamatsu, Masakazu Nakamura, Shyam S. Pandey

ACS Applied Materials and Interfaces 12 ( 10 ) 11876 - 11883 2020年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

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

DOI： 10.1021/acsami.9b23345

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

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

Japanese Journal of Applied Physics 2019年11月

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

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

materials ( MDIP ) 12 ( 21 ) 3643 2019年11月

担当区分：筆頭著者記述言語：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

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Role of device architecture and AlO<inf>X</inf> interlayer in organic Schottky diodes and their interpretation by analytical modeling 査読有り国際誌

Kumari N., Pandey M., Hamada K., Hirotani D., Nagamatsu S., Hayase S., Pandey S.

Journal of Applied Physics 126 ( 12 ) 2019年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Author(s). 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

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

Tripathi A., Sadakata S., Gupta R., Nagamatsu S., Ando Y., Pandey S.

ACS Applied Materials and Interfaces 11 ( 31 ) 28088 - 28095 2019年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 American Chemical Society. 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.

DOI： 10.1021/acsami.9b06568

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

Kumari N., Tripathi A., Sadakata S., Pandey M., Nagamatsu S., Hayase S., Pandey S.

Organic Electronics 68 221 - 229 2019年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Elsevier B.V. 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

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

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

Journal of Materials Chemistry C 7 ( 43 ) 13323 - 13351 2019年01月

記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

© The Royal Society of Chemistry 2019. 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 orientations of CPs. It summarizes the information for understanding the various techniques utilized for controlling the molecular ordering and macroscopic orientation in CP thin films in order to correlate device performance and anisotropic charge transport in OFETs. Systematic organization of topics and critical analysis of progress and improvisations are included, along with current state-of-The-Art approaches for each technique being discussed in detail. Apart from commentary on the pros and cons of various techniques, this review summarizes the future directions necessary for further development in the area of next-generation flexible electronics.

DOI： 10.1039/c9tc04397g

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

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

Organic Electronics 65 1 - 7 2018年10月

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

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

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

Tiwari S., Pandey M., Takashima W., Nagamatsu S., Balasubramanian S., Hayase S., Pandey S., Prakash R.

Organic Electronics: physics, materials, applications 56 152 - 158 2018年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Elsevier B.V. An effective approach for tuning the electronic characteristics of polymer-based organic field-effect transistors (OFETs) consisted of poly(3-hexylthiophene) (P3HT) doped with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and depleting layer formed by aluminum (Al) coating is being reported. Doping of P3HT was employed to accumulate and tune the carrier concentration while impleme ntation of depletion layer led to reduce the channel conductance. It has been demonstrated that on-currents in the OFETs were enhanced with the extent of TCNQ doping from 0% to 20% in the P3HT. Upon introduction of an ultra-thin Al led to the formation of depletion region resulting in to further decrease in the off-state current along with the improvement in the subthreshold characteristics. These two procedures provide counter-effects in terms of the on-state characteristics by doping and the off-state characteristics by depletion, which promotes switching performance in OFETs indicating the potentiality of doping technology for organic electronics.

DOI： 10.1016/j.orgel.2018.02.012

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

Pandey M., Gowda A., Nagamatsu S., Kumar S., Takashima W., Hayase S., Pandey S.

Advanced Materials Interfaces 5 ( 6 ) 2018年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 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 cm 2 V −1 s −1 along the backbone orientation, which is among the highest value reported for this class of materials using a similar device configuration.

DOI： 10.1002/admi.201700875

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

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

Applied Physics Letters 112 ( 12 ) 123301 2018年03月

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

Tripathi A., Pandey M., Sadakata S., Nagamatsu S., Takashima W., Hayase S., Pandey S.

Applied Physics Letters 112 ( 12 ) 2018年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Author(s). Fabrication of large area and uniform thin films with preferred edge-on orientation is highly demanded for flexible organic electronic devices. In this work, utilization of a newly designed slider in the floating film transfer method to assist unidirectional film spreading led to the fabrication of uniform and macroscopically edge-on oriented ribbon-shaped floating films (15 cm × 2 cm) having very large optical anisotropy (>20). The results pertaining to the in-plane grazing angle incident X-ray diffraction (GIXD) and φ-scan measurements revealed the well-stacked polymer backbone conformation with edge-on orientation without any inter-mixing of face-on oriented counterparts. Optical anisotropy dependent charge transport in organic field effect transistors using anisotropic poly(3,3‴-didodecyl-quaterthiophene) films has also been shown, and the results are supported by polarized electronic absorption and GIXD measurements.

DOI： 10.1063/1.5000566

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

Tripathi A., Pandey M., Nagamatsu S., Pandey S., Hayase S., Takashima W.

Journal of Physics: Conference Series 924 ( 1 ) 2017年12月

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）

© Published under licence by IOP Publishing Ltd. 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

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Interplay of Orientation and Blending: Synergistic Enhancement of Field Effect Mobility in Thiophene-Based Conjugated Polymers 査読有り国際誌

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

The Journal of Physical Chemistry C 121 ( 21 ) 11184 - 11193 2017年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

Trade-off between mechanical flexibility due to amorphicity and highly facile charge transport emanating from molecular crystallinity demands the orientation of conjugated polymers (CPs) for their utilization as active semiconducting material for flexible organic electronics. We have already demonstrated that it is rather easy to orient nonregiocontrolled poly(3-hexylthiophenes) (NR-P3HT) as compared to their highly regioregular counterparts due to very high alkyl chain interdigitation. To provide an amicable solution, efforts have been directed to orient blends of two CPs such as NR-P3HT (amorphous and flexible) and poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) (crystalline and facile charge transport) using a solution-based procedure floating film and transfer method (FTM). FTM-processed thin films of this blend system exhibited very high field effect transistor (FET) mobility reaching up to 0.1 cm2/V s, which is much higher than the corresponding individual CPs. In spite of only 10% incorporation of PBTTT in blend of NR-P3HT and PBTTT, there was a synergistically enhanced optical dichroic ratio (4.6 to 7.2) and FET mobility (8-fold) as compared to pristine NR-P3HT. At the same time, there was a 5-fold enhancement of FET mobility when 20% NR-P3HT was added in PBTTT as compared to that of PBTTT. This synergistic enhancement of charge carrier transport in the blend system has been explained by formation of oriented self-assembled fibrous domains of NR-P3HT and facile interdomain transport in crystalline PBTTT.

DOI： 10.1021/acs.jpcc.7b03416

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Layer-by-layer coating of oriented conjugated polymer films towards anisotropic electronics 査読有り国際誌

Pandey M., Sadakata S., Nagamatsu S., Nagamatsu S., Pandey S., Hayase S., Hayase S., Takashima W.

Synthetic Metals 227 29 - 36 2017年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017Dynamic 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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Solvent driven performance in thin floating-films of PBTTT for organic field effect transistor: Role of macroscopic orientation 査読有り国際誌

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

Organic Electronics: physics, materials, applications 43 240 - 246 2017年04月

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 cm2/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

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Controlling factors for orientation of conjugated polymer films in dynamic floating-film transfer method 査読有り国際誌

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

Journal of Nanoscience and Nanotechnology 17 ( 3 ) 1915 - 1922 2017年03月

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

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Synthesis, characterization and air stable semiconductor properties of thiophene-condensed pyrene derivatives 査読有り国際誌

Moriguchi T., Higashi M., Yakeya D., Jalli V., Tsuge A., Okauchi T., Nagamatsu S., Takashima W.

Journal of Molecular Structure 1127 413 - 418 2017年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 Elsevier B.V.New and simple polyaromatic compounds containing two thiophene rings were prepared via photo-cyclization and their structural and photophysical properties were evaluated via 1H NMR spectroscopy and X-ray crystallographic analysis. On the basis of X-ray analysis, it was determined that the molecular structure of the compound was highly strained and that they contain two hetero [4] helicene moieties. The compounds were investigated as active layer in p-type organic field-effect transistors (p-OFET) in top contact type devices. Notably, the compound containing two thiophene components exhibited very stable p-type semiconducting behavior in moist air.

DOI： 10.1016/j.molstruc.2016.07.104

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2016年度第1回九州支部市民講座「表面によって変化する物の性質—表面を見る？・調べる？・活用する？—」

永松秀一

表面科学 ( 公益社団法人日本表面科学会 ) 38 ( 7 ) 367 - 367 2017年01月

Influence of backbone structure on orientation of conjugated polymers in the dynamic casting of thin floating-films 査読有り国際誌

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

Thin Solid Films 619 125 - 130 2016年11月

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

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Enhancement of carrier mobility along with anisotropic transport in non-regiocontrolled poly (3-hexylthiophene) films processed by floating film transfer method 査読有り国際誌

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

Organic Electronics: physics, materials, applications 38 115 - 120 2016年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 Elsevier B.V.A newly developed floating film transfer method (FTM) has been successfully utilized to fabricate oriented thin films of non-regiocontrolled poly (3-hexyl thiophene) (NR-P3HT) followed by the fabrication of organic field effect transistors (OFETs). AFM microstructural investigations demonstrate the facile molecular alignment of NR-P3HT by FTM leading to highly oriented macromolecular assemblies like fibrous domains with considerably enhanced π-conjugation length. FTM thin films of NR-P3HT not only show enhanced optical anisotropy (dichroic ratio >8) but also significantly improved FET characteristics. FTM films in its parallel orientation exhibited a significant improvement (>2 orders) in the FET mobility as compared to its spin-coated device counterparts.

DOI： 10.1016/j.orgel.2016.08.003

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84982242946&origin=inward

Molecular structures of n-type semiconducting material 2, 5-difluoro-1, 4-phenylene-3, 3′-bis {2-[(4-trifluoromethyl) phenyl] acrylonitrile} and its photo dimerization product 査読有り

Tetsuji Moriguchi, Naoya Kitou, Venkataprasad Jalli, Kenji Yoza, Shuichi Nagamatsu, Tatsuo Okauchi, Akihiko Tsuge, Wataru Takashima

Journal of Molecular Structure 2016年08月

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

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

Journal of Physics: Conference Series 704 ( 1 ) 2016年04月

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）

Orientation characteristics of non-regiocontrolled poly (3-hexylthiophene) (NR-P3HT) films prepared by dynamic casting of floating film and transferring method (FTM) has been investigated. The film was first cast on liquid-substrate to obtain as a floating-film followed by its transfer on solid-substrate such as white-glass or Si-wafer in order to evaluate their optoelectronic characteristics. As a possible key-factor to generate the orientation of conjugated polymer in this method we focused on the components of liquid-substrate in this study. The orientation dependence upon various liquid-substrates reveals that dichroic ratio strongly changes with liquid-substrates. Pictures of floating-film show the change in size of floating-parts depending upon the liquid-substrate, representing the expansion length of casting solution upon the viscosity. These findings have indicated that spreading speed of polymer solution and solvent evaporation speed controls the size of floating-film leading to change in the orientation intensity. The multilayer coatings of oriented NR-P3HT films were used for polarized FTIR analysis exhibiting clear dichroism. The obtained dichroic characteristics were well corresponded with in-plane, out-of-plane and non-oriented vibronic modes of P3HT.

DOI： 10.1088/1742-6596/704/1/012005

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A comparative study of spin coated and floating film transfer method coated poly (3-hexylthiophene)/poly (3-hexylthiophene)-nanofibers based field effect transistors 査読有り

Shashi Tiwari, Wataru Takashima, S Nagamatsu, SK Balasubramanian, Rajiv Prakash

Journal of Applied Physics 116 ( 9 ) 094306 2014年09月

Molecular Structure and Crystal Packing of n-Type Semiconducting Material 3',3'-(1,4-Phenylene) bis {2'-(4"-trifluoromethyl) phenyl} acrylonitrile 査読有り国際誌

Tetsuji Moriguchi, Shuichi Nagamatsu, Tatsuo Okauchi, Akihiko Tsuge, Wataru Takashima, Shuji Hayase

Journal of Crystallography 2014 2014年08月

P3HT-fiber-based field-effect transistor: Effects of nanostructure and annealing temperature 査読有り国際誌

Shashi Tiwari, Wataru Takashima, Sirkazhi Krithivasan Balasubramanian, Shougo Miyajima, Shuichi Nagamatsu, Shyam Sudhir Pandey, Rajiv Prakash

Japanese Journal of Applied Physics 53 ( 2 ) 021601 2014年02月

Fabrication of Large-scale Drop-cast Films of π-conjugated Polymers with Floating-film Transfer Method 査読有り国際誌

Dauendorffer Arnaud, Rajiv K Pandey, Syougo Miyajima, Shuichi Nagamatsu, Rajiv Prakash, Wataru Takashima, Shuzi Hayase, Keiichi Kaneto

Transactions of the Materials Research Society of Japan 38 ( 2 ) 305 - 308 2013年12月

Macroscopic self ordering of solution processible poly (3,3'-dialkylquaterthiophene) by floating film transfer method 査読有り国際誌

Rajiv K Pandey, Wataru Takashima, Shuichi Nagamatsu, Arnaud Dauendorffer, K Kaneto, Rajiv Prakash

Journal of Applied Physics 114 ( 5 ) 054309 2013年08月

Electrophoretic deposition onto an insulator for thin film preparation toward electronic device fabrication 査読有り国際誌

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

Applied Physics Letters 101 ( 19 ) 193305 2012年11月

One-Step Deposition of Self-Oriented β-Phase Polyfluorene Thin Films for Polarized Polymer Light-Emitting Diodes 査読有り国際誌

Arnaud Dauendorffer, Shougo Miyajima, Shuichi Nagamatsu, Wataru Takashima, Shuzi Hayase, Keiichi Kaneto

Applied Physics Express 5 ( 9 ) 092101 2012年09月

Optical and Transport Anisotropy in Poly(9,9'-dioctyl-fluorene-alt-bithiophene) Films Prepared by Floating Film Transfer Method 査読有り国際誌

Arnaud Dauendorffer, Shuichi Nagamatsu, Wataru Takashima, Keiichi Kaneto

Japanese Journal of Applied Physics 51 ( 5 ) 055802 6頁 2012年04月

Bis(alkyl-thiophene) thienothiophene as hole-transport organic semiconductor 査読有り国際誌

Kazuhiro Takamiya, Shuhei Ishikawa, Daisuke Adachi, Shinya Oku, Shuichi Nagamatsu, Wataru Takashima, Shuzi Hayasea, Keiichi Kaneto

Physics Procedia 14 182 - 186 2011年07月

ポリチオフェン、オリゴチオフェンの配向制御とデバイス応用査読有り

谷垣宣孝, 武智恭世, 溝黒登志子, HECK Claire, 永松秀一, 吉田郵司

Molecular electronics and bioelectronics 22 ( 2 ) 119 - 122 2011年05月

アルキルチオフェン-チエノチオフェン誘導体の正孔輸送特性と大気安定性査読有り

石川修平, 永松秀一, 高嶋授, 金藤敬一

電子情報通信学会技術研究報告. SDM, シリコン材料・デバイス 111 ( 4 ) 47 - 50 2011年04月

記述言語：日本語掲載種別：研究論文（学術雑誌）

アルキルチオフェンで修飾されたシンプルな分子構造を有する低分子有機半導体の正孔輸送特性と大気安定性について調査した。チエノチオフェンを中心骨格に有する誘導体では、アルキル末端鎖長が6,8で最大移動度が観測された。一方、アルキル末端鎖長8,12で乾燥大気下での優れた安定性が観測された。AFM測定結果から、アルキル末端鎖長により膜形態が変化することがわかった。正孔輸送特性及び大気安定性を、膜形態との相関で詳細に議論した。

その他リンク： http://ci.nii.ac.jp/naid/110008689382

浮遊薄膜転写法を用いた可溶性有機半導体の電気的、光学的異方性 : 高配向薄膜の製膜査読有り

本間亮嗣, 永松秀一, 金藤敬一, 高嶋授

電子情報通信学会技術研究報告. SDM, シリコン材料・デバイス 111 ( 4 ) 51 - 54 2011年04月

記述言語：日本語掲載種別：研究論文（学術雑誌）

貧溶媒液表面をキャスト基板として用いる浮遊薄膜転写法を用いて、可溶性高分子有機半導体の大面積キャスト膜を作成した。可溶性高分子半導体としてポリクウォーターチオフェンを用いた場合、直径約5cm程度の大きな同心円状異方性を有する高配向膜を容易に形成することが出来た。得られた高配向高分子半導体薄膜について電気的、光学的異方性と、表面モルフォロジーを調査した。

その他リンク： http://ci.nii.ac.jp/naid/110008689383

チエニレンビニレン誘導体の合成と光電気物性査読有り

田原可南子, ダウエンドルファーアルノ, 永松秀一, 高嶋授, 金藤敬一

電子情報通信学会技術研究報告. SDM, シリコン材料・デバイス 111 ( 4 ) 55 - 58 2011年04月

記述言語：日本語掲載種別：研究論文（学術雑誌）

アルキル置換チエニレンビニレンのポリマーおよびオリゴマーを合成し、その光電気特性について調査した。それぞれの材料はマクマリー反応および右田小杉スティレカップリングにより合成した。チエニレンビニレンポリマーは長波長領域に光吸収を示したものの有機溶媒に対して難溶性であった。チエニレンビニレンオリゴマーは有機溶媒に易溶性を示し、分子長に起因した光吸収を示した。特にチオフェン環を8つ有するオリゴマーはポリ(3-へキシルチオフェン)よりも長波長領域に光吸収を示した。チエニレンビニレンポリマーおよびオリゴマーを用いた有機薄膜太陽電池は、オリゴマーを用いた場合のほうが高い変換効率を示した。これはオリゴマー化することで、有機溶媒への溶解性の向上と分子量分布の狭帯化による電荷輸送能の向上に起因すると考えられる。

その他リンク： http://ci.nii.ac.jp/naid/110008689384

Robust Hole Transport in a Thienothiophene Derivative toward Low-cost Electronics 査読有り国際誌

Shinya Oku, Kazuhiro Takamiya, Daisuke Adachi, Shuhei Ishikawa, Shuichi Nagamatsu, Wataru Takashima, Shuzi Hayase, Keiichi Kaneto

Chemistry Letters 39 ( 12 ) 1315 - 1316 2010年11月

Ambipolar characteristics of solution processed bilayer field effect transistors based on poly(3-hexylthiophene) and fullerene derivatives 査読有り

Morita T., Nagamatsu S., Singh V., Oku S., Takashima W., Kaneto K.

Materials Research Society Symposium Proceedings 1115 53 - 58 2010年05月

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）

Ambipolar organic field effect transistors (AOFET) based on the bilayer structure of poly(3-hexylthiophene) (P3HT) as the upper layer and [6, 6]-phenyl-C 61-butyric methyl ester (PCBM) as the bottom layer have been fabricated. A novel method, namely, direct film transfer (DFT) technique was developed to put the top layer on the spin coated bottom layer. The method did not seriously erode the bottom layer. The mobilities obtained from AOFET were 1, 7× 10 -5 cm 2/Vs for hole and 1.5 × 10 -3 cm 2/Vs for electron. The characteristics and (hole and electron) mobilities in the ambipolar bilayer FET showed better performance compared with those of P3HT and PCBM blended film. The results were discussed with the performances of the respective single layer FETs. © 2009 Materials Research Society.

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Ambipolar Transport in Bilayer Organic Field-Effect Transistor Based on Poly(3-hexylthiophene) and Fullerene Derivatives 査読有り国際誌

Takeomi Morita,Shign Vipul,Shinya Oku,Shuichi Nagamatsu,Wataru Takashima,Shuzi Hayase,Keiichi Kaneto

JAPANESE JOURNAL OF APPLIED PHYSICS 49 ( 4 ) 041601.1 - 041601.5 2010年04月

Solution-processable Oligothiophene Derivatives with Branched Alkyl Chains and Their Thin-film Transistor Characteristics 査読有り国際誌

Lu Ming,Shuichi Nagamatsu,Yuji Yoshida,Masayuki Chikamatsu,Reiko Azumi,Kiyoshi Yase

Chemistry Letters 39 60 - 61 2010年01月

Comparative Study on Gate Insulators of Polymers and SiO2 in Transport Properties of p- and n-Type Organic Field-Effect Transistors 査読有り国際誌

Shinya Oku,Toshiya Nagase,Shuichi Nagamatsu,Wataru Takashima,Keiichi KAneto

JAPANESE JOURNAL OF APPLIED PHYSICS 49 ( 1 ) 01AB14.1 - 01AB14.4 2010年01月

Molecular orientation of poly(3-butylthiophene) friction-transferred films 査読有り国際誌

Nobutaka Tanigaki,Shuichi Nagamatsu,Wataru Takashima,Yuji Yoshida

Thin Solid Films 518 ( 2 ) 853 - 856 2009年11月

Enhancement of Transport Characteristics in Poly(3-hexylthiophene) Films Deposited with Floating Film Transfer Method 査読有り国際誌

Morita Takeomi, Singh Vipul, Nagamatsu Shuichi, OKU Shinya, TAKASHIMA Wataru, KANETO Keiichi

Applied physics express ( Japan Society of Applied Physics ) 2 ( 11 ) "111502 - 1"-"111502-3" 2009年11月

Multi-Layered Oriented Polyfluorene Films 査読有り国際誌

Shuichi Nagamatsu,Masahiro Misaki,Yuji Yoshida,Reiko Azumi,Nobutaka Tanigaki,Kiyoshi Yase

The Journal of Physical Chemistry B 113 ( 17 ) 5746 - 5751 2009年04月

[6.6]-Phenyl C_<61>-Butyric acid Methyl ester (PCBM) 溶液の形成プロセスとn型FET特性査読有り

濱地孝輔, 森田壮臣, 永松秀一, 高嶋授, 桑島修一郎, 金藤敬一

電子情報通信学会技術研究報告. OME, 有機エレクトロニクス ( 一般社団法人電子情報通信学会 ) 109 ( 20 ) 1 - 4 2009年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

溶液からの成膜法により形成される数少ないn型有機半導体材料である、可溶性フラーレン誘導体[6.6]-Phenyl C_<61>-Butyric acid Methyl ester(PCBM)を活性層とするn型有機電界効果トランジスタ(OFET)のFET特性と、溶液の攪拌時間との相関について調査した。攪拌時間の増加と共に、オフ電流は大きく変動し、約3時間程度の攪拌によりオフ電流は最小となり、これに伴い最大のオンオフ比が得られた。

その他リンク： https://ci.nii.ac.jp/naid/110007227494

高歪みフェン系多環芳香族化合物の合成とその物性査読有り

田崎祭, 森口哲次, 柘植顕彦, 永松秀一, 高嶋授

基礎有機化学討論会要旨集（基礎有機化学連合討論会予稿集） ( 基礎有機化学会（基礎有機化学連合討論会） ) 2009 ( 0 ) 312 - 312 2009年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

新たな有機半導体材料を合成し、その構造特性、光化学特性及び電気伝導特性の評価を検討した。溶解性に関しては、溶解性の向上が期待されるt-butyl基を導入し、デバイス特性に対してはピレンを出発原料に用いてオリゴチオフェン鎖を導入することで向上を試みた。また、X線構造解析及びFETを作成し変位電流測定を行うことにより積層性や電気伝導特性の検討を行った。

DOI： 10.11494/kisoyuki.2009.0.312.0

その他リンク： https://ci.nii.ac.jp/naid/130004728938

Polarized white emission from polymer LEDs of aligned binary blend 査読有り国際誌

Hijikata Y., Misaki M., Nagamatsu S., Chikamatsu M., Yoshida Y., Azumi R., Tanigaki N., Yamashita M., Yase K.

IDW '08 - Proceedings of the 15th International Display Workshops 2 1063 - 1064 2008年12月

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 demonstrate polymer light-emitting diodes with polarized white emission for liquid crystal display backlights application. Polarized white emission was realized by spin-coating a mixed solution of blue emissive polymer and orange emissive polymer onto an alignment layer. Our devices turned on at 3.5 V and reached a brightness of 1830 cd/m2 at 10.0 V with an efficiency of 0.4 cd/A. The integrated polarization ratio was estimated to be 2.4 with the CIE coordinates of (0.33, 0.34).

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Highly efficient polarized polymer light-emitting diodes utilizing oriented films of beta-phase poly(9,9-dioctylfluorene) 査読有り国際誌

Masahiro Misaki,Masayuki Chikamatsu,Yuji Yoshida,Reiko Azumi,Nobutaka Tanigaki,Kiyoshi Yase,Shuichi Nagamatsu,Yasukiyo Ueda

Applied Physics Letters 93 ( 2 ) 023304 - 023304.3 2008年07月

Side-Chain Effects on Friction-Transferred Polymer Orientation 査読有り国際誌

Nagamatsu Shuichi, Misaki Masahiro, Kimura Tatsumi, YOSHIDA Yuji, AZUMI Reiko, TANIGAKI Nobutaka, YASE Kiyoshi

Polymer journal ( Society of Polymer Science, Japan ) 39 ( 12 ) 1300 - 1305 2007年12月

Single-crystal-like structure of poly(9,9-dioctylfluorene) thin films evaluated by synchrotron-sourced grazing-incidence X-ray diffraction 査読有り国際誌

Misaki M., Nagamatsu S., Chikamatsu M., Yoshida Y., Azumi R., Tanigaki N., Ueda Y., Yase K.

Polymer Journal 39 ( 12 ) 1306 - 1311 2007年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Detailed structures of friction-transferred poly(9,9-dioctylfluorene) (PFO) thin films have been studied using synchrotron-sourced grazing-incidence X-ray diffraction (GIXD). The results of in-plane GIXD were in full agreement with those of electron diffraction in our previous study. We also revealed the structures of liquid-crystalline (LC) and crystalline films that were prepared by rapid and slow cooling from the LC melted state of the friction-transferred films, respectively. For the crystalline films, the results of in-plane GIXD were not in full agreement with those of electron diffraction; additional weak peaks of the odd 001 reflections were observed only in the GIXD profiles. This implies that the twofold screw symmetry along the c-axis of PFO is broken. The rocking profiles for each reflection gave the order parameter of almost one for the crystalline films and 0.67 for the LC films. These results suggest the ability of friction transfer for obtaining single-crystal-like thin films and the importance of carefully designed annealing process for the applications of the films to various optoelectronic devices. © 2007 The Society of Polymer Science.

DOI： 10.1295/polymj.PJ2007063

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Unipolarization of ambipolar organic field effect transistors toward high-impedance complementary metal-oxide-semiconductor circuits 査読有り国際誌

Takashima W., Murasaki T., Nagamatsu S., Morita T., Kaneto K.

Applied Physics Letters 91 ( 7 ) 2007年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ambipolar organic field effect transistors (OFETs), consisting of a composite of polyhexylthiophene (PHT) and [6,6]-phenyl C61-butylic acid methyl ester (PCBM), was converted into a p - or n -type OFET by insertion of a thin tetracyanoquinodimethane (TCNQ) or tetrathiafluvalene (TTF) buffer layer. The interface in the Au/TCNQ/PHT:PCBM composite transports hole but blocks electron, while the transported carrier was switched to electron with insertion of a TTF layer. The selective transport is probably due to vacuum level matching or temporal doping. High impedance in a complementary metal-oxide-semiconductor inverter was demonstrated with unipolarized ambipolar FETs, resulting in a decrease in the through current. © 2007 American Institute of Physics.

DOI： 10.1063/1.2770963

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=34548022859&origin=inward

Structure and Electrical Properties of Unsubstituted Oligothiophenes End-Capped at the β-Position 査読有り国際誌

Jiro Chisaka,Ming Lu,Shuichi Nagamatsu,Masayuki Chikamatsu,Yuji Yoshida,Midori Goto,Reiko Azumi,Masafumi Yamashita,Kiyoshi Yase

Chemistry of Materials 19 ( 10 ) 2694 - 2701 2007年05月

ポリフルオレン積層配向膜の作製及び構造評価

永松秀一,三崎雅裕,吉田郵司,阿澄玲子,谷垣宣孝,八瀬清志

信学技報 107 ( 13 ) 11 - 15 2007年04月

Highly efficient polarized polymer light-emitting diodes prepared by friction-transfer technique 査読有り国際誌

Misaki M., Nagamatsu S., Chikamatsu M., Yoshida Y., Tanigaki N., Azumi R., Ueda Y., Yase K.

IDW '06 - Proceedings of the 13th International Display Workshops 2 1299 - 1301 2006年12月

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 demonstrate highly efficient polarized polymer light-emitting diodes (p-PLEDs) for liquid crystal display (LCD) backlights application. The optimization of the device structure drastically improves the performance of p-PLEDs: the devices turn on at 4 V and reach a brightness of 1793 cd/m 2 at 12.5 V with an efficiency of 1.23 cd/A. The electroluminescent (EL) dichroic ratio (integrated intensity) is estimated to be 45.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=57649176631&origin=inward

Structure of friction-transferred poly(p-phenylenevinylene) derivative thin films 査読有り国際誌

Nagamatsu S., Misaki M., Kimura T., Yoshida Y., Tanigaki N., Yase K.

Polymer Preprints, Japan 55 ( 1 ) 2006年10月

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（国際会議プロシーディングス）

Poly(1,4-phenylenevinylene) derivatives (PPVs) were found to form highly oriented film by a friction-transfer technique. The structural information of molecular arrangement in the friction-transferred PPVs film was investigated by polarized optical properties measurements and synchrotron-sourced grazing incidence X-ray diffraction (GIXD) analyses. The GIXD profiles of DOPPV film indicated that the polymer molecules in the friction-transferred film were perfectly arranged three-dimensionally. On the other hand, the GIXD profiles of BEHPPV film showed a quite different polymer arrangement from that of DOPPV. The polymer molecules arrangement in the friction-transferred PPVs film was found to be depending on the side-chain structure of that.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=33749654063&origin=inward

Structure of oriented thin films of polythiophene and its derivatives by friction transfer method 査読有り国際誌

Takechi C., Nagamatsu S., Yoshida Y., Kaneko F., Tanigaki N.

Polymer Preprints, Japan 55 ( 1 ) 2006年10月

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）

Structure of highly oriented thin films of polythiophene, which were prepared by friction transfer method, was investigated using grazing-incidence X-ray diffraction (GIXD), ultraviolet-visible spectra,infrared spectra, and Raman scattering. GIXD measurements clarified that the polymer backbones were aligned with very narrow distribution. The degree of orientation of polythiophene was high compared with those of regioregular poly(3- alkylthiophene)s.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=33749681910&origin=inward

in situ grazing incidence x-ray diffraction study of friction-transferred poly(9,9-dioctylfluorene) thin films 査読有り国際誌

Masahiro Misaki,Shuichi Nagamatsu,Masayuki Chikamatsu,Yuji Yoshida,Nobutaka Tanigaki,Kazuhiko Omote,Kiyoshi Yase,Yasukiyo Ueda

2005 International Chemical Congress of Pacific Basin Societies 858 - 858 2005年12月

Structure investigation of friction-transferred poly(2,5-dioctyloxy-1,4-phenylenevinylene) thin film 査読有り国際誌

Shuichi Nagamatsu,Masahiro Misaki,Yuji Yoshida,Nobutaka Tanigaki,Kiyoshi Yase

2005 International Chemical Congress of Pacific Basin Societies 0875 - 0875 2005年12月

Highly polarized polymer light-emitting diodes utilizing friction-transferred poly(9,9-dioctylfluorene) thin films 査読有り国際誌

Misaki M., Ueda Y., Nagamatsu S., Chikamatsu M., Yoshida Y., Tanigaki N., Yase K.

Applied Physics Letters 87 ( 24 ) 1 - 3 2005年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Polarized polymer light-emitting diodes (PLEDs) have been constructed utilizing friction-transferred poly(9,9-dioctylfluorene) (PFO) thin films. The friction transfer technique allows oriented PFO to be deposited directly onto an indium tin oxide anode without an alignment layer such as polyimide. Polarized absorption and photoluminescence spectra revealed that the polymer backbones are highly aligned in the friction direction. We fabricated PLEDs consisting of friction-transferred PFO as an emissive layer, vacuum-deposited bathocuproine as an electron transport and hole-blocking layer, and a vacuum-deposited LiFAl cathode. Highly polarized blue emission with an integrated polarization ratio of 31 and a luminance of up to 300 cd m2 was observed from the PLEDs. © 2005 American Institute of Physics.

DOI： 10.1063/1.2142082

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Highly anisotropic blue organic electroluminescent devices prepared by friction-transfer technique of poly(9,9-dioctylfluorene) 査読有り国際誌

Misaki M., Nagamatsu S., Chikamatsu M., Yoshida Y., Azumi R., Tanigaki N., Ueda Y., Yase K.

IDW/AD'05 - Proceedings of the 12th International Display Workshops in Conjunction with Asia Display 2005 ( 2 ) 1289 - 1290 2005年12月

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）

Highly oriented polyfluorene thin film was fabricated by using a friction-transfer technique to estimate the anisotropic features in molecular orientation and optical properties. It was found that the electroluminescence from this device was really polarized with the ratio of more than 30.

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Solution-processed n -type organic thin-film transistors with high field-effect mobility 査読有り国際誌

Chikamatsu M., Nagamatsu S., Yoshida Y., Saito K., Yase K., Kikuchi K.

Applied Physics Letters 87 ( 20 ) 1 - 3 2005年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

We report the performance of solution-processed n -type organic thin-film transistors (OTFTs) based on C60 derivatives. Long-chain alkyl-substituted C60, C60-fused N -methylpyrrolidine-meta-C12 phenyl (C60MC12), was used as a semiconducting layer. The C60MC12-thin-film transistor shows high electron mobility of 0.067 cm2 V s in saturation regime. From the result of x-ray diffraction analysis, the C60MC12 active layer forms highly ordered crystalline film. We found that self-assemble ability of long alkyl chains plays an important role for fabrication of highly ordered crystalline film, leading to achievement of high electron mobility in solution-processed n -type OTFTs. © 2005 American Institute of Physics.

DOI： 10.1063/1.2130712

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Correlation of the Number of Thiophene Units with Structual Order and Carrier Mobility in Unsubstituted Even- and Odd-Numbered alpha-Oligothiophene Films 査読有り国際誌

Shuichi Nagamatsu,Keiichi Kaneto,Reiko Azumi,Mutsuyoshi Matsumoto,Yuji Yoshida,Kiyoshi Yase

Journal of Physical Chemistry B 109 ( 19 ) 9374 - 9378 2005年05月

摩擦転写法による高分子配向膜とその分子配列

永松秀一,三崎雅裕,吉田郵司,谷垣宣孝,八瀬清志

信学技報 105 ( 8 ) 31 - 36 2005年04月

分子長の異なるオリゴチオフェンの構造とFET(<小特集>有機結晶の新展開) 査読有り

阿澄玲子, 永松秀一, 後藤みどり, 吉田郵司, 八瀬清志

日本結晶成長学会誌 ( 日本結晶成長学会 ) 32 ( 5 ) 365 - 370 2005年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

本稿では,優れた特性を示す有機半導体として注目されている無置換α-オリゴチオフェンを材料に,そのバルクでの結晶構造と薄膜で出現する結晶相,また,電荷移動度との関係について論じる.単結晶構造解析の結果から,5量体および7量体では,偶数のチオフェン環をもつオリゴマーに比べ,結晶内での分子のコンフォメーションの乱れが大きくなる傾向があることが明らかになった.また,5量体および7量体では,蒸着条件によって2つの結晶相が薄膜内に共存する場合があった.チオフェン環の数の偶奇は,薄膜の成長様式に差異を与え,結果的に薄膜トランジスタの物性に影響を与えうることが明らかになった.

DOI： 10.19009/jjacg.32.5_365

その他リンク： https://ci.nii.ac.jp/naid/110007327718

C60 thin-film transistors with low work-function metal electrodes 査読有り国際誌

Masayuki Chikamatsu,Shuichi Nagamatsu,Tetuya Taima,Yuji Yoshida,Natsuko Sasaki,Harumi Yokokawa,Kazuhiko Saito,Kiyoshi Yase

Applied Physics Letters 85 ( 12 ) 2396 - 2398 2004年09月

Formation of single-crystal-like poly(9,9-dioctylfluorene) thin film by the friction-transfer technique with subsequent thermal treatments 査読有り国際誌

Masahiro Misaki,Yasukiyo Ueda,Shuichi Nagamatsu,Yuji Yoshida,Nobutaka Tanigaki,Kiyoshi Yase

Macromolecules 37 ( 18 ) 6926 - 6931 2004年09月

液晶性高分子ポリフルオレン高配向膜のその場GIXD観察

三崎雅裕,永松秀一,吉田郵司,谷垣宣孝,表和彦,八瀬清志,上田裕清

KEK Proceedings PF・KENS合同研究会「ナノサイエンス・テクノロジーと放射光/中性子反射率法」 5 66 - 67 2004年04月

有機半導体薄膜の分子配向制御と光電子機能デバイスへの応用

吉田郵司,永松秀一,谷垣宣孝,八瀬清志

応用物理学会有機分子・バイオエレクトロニクス分科会会誌 15 147 - 150 2004年04月

Organic field-effect transistors by a wet-transferring method 査読有り国際誌

Noh Y., Kim J., Yase K., Nagamatsu S.

Applied Physics Letters 83 ( 6 ) 1243 - 1245 2003年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

A study was performed on organic field-effect transistors (OFET). They were prepared from an epitaxially grown film, which was fabricated by using a wet-transferring process. It was found that the calculated μFETof the OFET for the wet-transferred vertically aligned film were 1.3×10-4and 2.2×10-4cm2V-1s-1at the linear and saturation regions respectively.

DOI： 10.1063/1.1600518

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Effects of molecular alignment on carrier transport in organic transistors 査読有り国際誌

Nagamatsu S., Tanigaki N., Yoshida Y., Takashima W., Yase K., Kaneto K.

Synthetic Metals 137 ( 1-3 ) 923 - 924 2003年04月

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（国際会議プロシーディングス）

The application of molecular alignment to conjugated polymers offers a unique approach for constructing organic semiconductor devices. We made polymer thin film field-effect transistors (FET) by friction-transfer technique, based on regioregular poly(3-alkylthiophene) (P3AT). Friction-transferred films of P3AT were found to align approximately all of the polymer main-chains within a 9-13 ° range along the friction direction. When introduced in FET devices, the mobility anisotropies of 5-20 for current flow parallel and orthogonal to the friction direction has been observed. In addition, when compared with conventional isotropic FET devices of non-aligned P3AT films, they were found to enhance the mobility by a factor of 2-70.

DOI： 10.1016/S0379-6779(02)01184-0

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LiF/Al bilayer source and drain electrodes for n-channel organic field-effect transistors 査読有り国際誌

Hoshino S., Nagamatsu S., Chikamatsu M., Misaki M., Yoshida Y., Tanigaki N., Yase K.

Synthetic Metals 137 ( 1-3 ) 953 - 954 2003年04月

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 investigated electronic effects of an ultrathin LiF interlayer on device properties of copper(II) perfluorophthalocyanine (F16CuPc)-based field effect transistors (FETs) with Al source and drain electrodes. We observed FET operation only for the device with LiF/Al bilayer electrodes. We concluded that an effective electronic contact was formed between Al and F16CuPc layer by the presence of the LiF layer, which prevented the F16CuPc layer from reacting with Al and n-doped with dissociated Li atoms in the vicinity of the source and drain electrodes.

DOI： 10.1016/S0379-6779(02)00945-1

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Device Performance of an n-Channel Organic Thin-Film Transistor with LiF/Al Bilayer Source and Drain Electrodes 査読有り国際誌

Satoshi Hoshino,Shuichi Nagamatsu,Masayuki Chikamatsu,Masahiro Misaki,Yuji Yoshida,Nobutaka Tanigaki,Kiyoshi Yase

Japanese Journal of Applied Physics 41 ( 7A ) L808 - L810 2002年07月

Device performance of an n-channel organic thin-film transistor with LiF/Al bilayer source and drain electrodes 査読有り国際誌

Hoshino S., Nagamatsu S., Chikamatsu M., Misaki M., Yoshida Y., Nobutk Tnigki A., Yase K.

Japanese Journal of Applied Physics, Part 2: Letters 41 ( 7 A ) 2002年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

We investigated the device properties of a copper (II) perfluorophthalocyanine (F 16CuPc)-based n-channel organic thin-film transistor (TFT) with source and drain electrodes consisting of an LiF/Al bilayer. We clarified that the LiF thin film intercalated between the F 16CuPc and Al layers played a key role in the observed field-effect transistor characteristics of the TFT. We concluded that the contact resistance was effectively reduced by the LiF layer, providing protection against an unfavorable chemical reaction with Al and possible formation of n-doped regions in the vicinity of the LiF/Al electrodes of the F 16CuPc layer.

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LiF/Al bilayer source and drain electrodes for n-channel organic field-effect transistors 査読有り国際誌

Satoshi Hoshino,Shuichi Nagamatsu,Masayuki Chikamatsu,Masahiro Misaki,Yuji Yoshida,Nobutaka Tanigaki,Kiyoshi Yase

Synthetic Metals 137 953 - 954 2002年04月

Polarization sensitive photoelectric conversion by polymer/titania bilayer 査読有り国際誌

N Tanigaki , S. Kuwajima , S. Nagamatsu , Y. Yoshida , K. Yase

Synthetic Metals 137 1425 - 1426 2002年04月

Effect of molecular alignment on carrier transport in organic transistors 査読有り国際誌

Shuichi Nagamatsu,Yuji Yoshida,Nobutaka Tanigaki,Wataru Takashima,Kiyoshi Yase,Keiichi Kaneto

Synthetic Metals 137 923 - 923 2002年04月

共役高分子/チタニア二層膜の偏光応答光電変換

谷垣宣孝,吉田郵司,永松秀一,桑島修一郎,八瀬清志

信学技報 102 13 - 16 2002年04月

GIXDによるポリチオフェン誘導体の高配向超薄膜の構造評価

永松秀一,吉田郵司,谷垣宣孝,高嶋授,八瀬清志,金藤敬一

KEK Proceedings「X線・中性子反射率/散乱法による薄膜・多層膜の構造評価」 25 56 - 57 2001年04月

Dispersivity of carrier transport related with molecular arrangement in regioregular poly(3-alkylthiophene) 査読有り国際誌

Takashima W., Nagamatsu S., Pandey S., Endo T., Yoshida Y., Tanigaki N., Rikukawa M., Yase S., Kaneto K.

Synthetic Metals 119 ( 1-3 ) 563 - 564 2001年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

The carrier transport was investigated depending upon the processes of film preparation in regioregular poly(3-alkylthiophene)s (PATs). The relatively non-dispersive characteristics of photocarrier transport were obtained in drop-cast film. In spin-coated film the transient photocurrent was strong dispersive in contrast. The dispersivity was also slightly increased with the alkyl chain length. The X-ray profiles showed the large crystallinity and the absorption spectra showed the red-shift of peaks in drop-cast film. These results indicate that the dispersivity of carrier transport in PATs is strongly affected by the casting processes of PAT film.

DOI： 10.1016/S0379-6779(00)01194-2

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Photocarrier transport in processable poly(3-alkylthiophene) 査読有り

Nagamatsu S., Pandey S., Takashima W., Endo T., Rikukawa M., Kaneto K.

Synthetic Metals 121 ( 1-3 ) 1563 - 1564 2001年03月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Photocarrier transport in soluble poly(3-alkylthiophenes)(PATS) has been studied by means of time of flight method. Temperature and field dependencies of mobility were measured for a number of polythiophene derivatives having various alkyl chain lengths from butyl to octadecyl. It has been found that regioregularity has a marked effect on hole mobility in PATs with shorter alkyl group. The results of the mobility in PAT films are discussed in terms of main chain regularity and alkyl chain lengths.

DOI： 10.1016/S0379-6779(00)01499-5

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Mechanism of Photocarrier Generation and Transport in Poly(3-Alkylthiophene) Films 査読有り

Shyam S. Pandey,Shuichi Nagamatsu,Wataru Takashima,Keiichi Kaneto

Japanese Journal of Applied Physics 39 ( 11 ) 6309 - 6315 2000年11月

Dependencies of Field Effect Mobility on Regioregularity and Side Chain Length in Poly (Alkylthiophene) Films 査読有り国際誌

LIM Wee Yee, NAGAMATSU Shuichi, TAKASHIMA Wataru, ENDO Takeshi, RIKUKAWA Masahiro, KANETO Keiichi

IEICE transactions on electronics ( 一般社団法人電子情報通信学会 ) 83 ( 7 ) 1071 - 1075 2000年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

Carrier mobilities in poly(3-alkylthiphene) cast films have been studied by means of fabricating a field effect transistor (FET) at the field range of (0.4-1.6)×10^4V / cm. It is found that the regioregurality is markedly effective to the mobilities than the side chain length. The FET mobility of the regioregular poly(3-hexylthiophene), PHT is approximately 3×10^<-3>cm^2 / Vs which is larger than that of regiorandom PHT by 3 orders of magnitude. The mobility of regioregular poly(3-dodecylthiophene), PDDT is 8×10^<-4>cm^2 / Vs and is also 3 orders of magnitude larger than that of regiorandom PDDT. The mobilities of regioregular ones decrease, however, those of regiorandom ones increase at higher fields. The FET mobilities are nearly same to the mobilities estimated by the time of flight method. These results have been discussed taking the regularity of the main chain and the length of side chain into consideration.

その他リンク： https://ci.nii.ac.jp/naid/110003211948

Effect of Synthetic Impurities on Photocarrier Transport in Poly (3-Hexylthiophene) 査読有り

PANDEY Shyam S., TAKASHIMA Wataru, NAGAMATSU Shuichi, KANETO Keiichi

IEICE transactions on electronics ( 一般社団法人電子情報通信学会 ) 83 ( 7 ) 1088 - 1093 2000年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

Photocarrier transport of regiorandom poly(3-hexylthiophene) P3HT in ITO / P3HT / Al sandwich cell configuration has been investigated by means of Time-of-Flight technique. Characteristics of Schottky diode and the magnitude of hole mobility have been found to be affected by impurities involved during the synthesis. The hole mobility in regiorandom P3HT at room temperature has been estimated to be 2.4×10^<-5>and 2.6×10^<-4>cm^2 / V.s before and after the removal of ferric ions, respectively, at a field of 5.0×10^5V / cm. Field dependencies of mobility before and after purification show unique feature and have been discussed in terms of the disorder model.