研究者詳細 - 永松　秀一

論文 - 永松　秀一

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

Shuichi Nagamatsu, Shyam S. Pandey

Scientific Reports ( Springer Nature ) 10 ( 1 ) 20020 2020年11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（学術雑誌）

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

Kyutacar

Scopus

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

Scopus

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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

Scopus

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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

Scopus

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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

Scopus

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

Scopus

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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

Scopus

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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

Scopus

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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.

Scopus

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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

Scopus

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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

Scopus

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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

Scopus

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