Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Katsuhiko FUJITA Last modified date:2020.06.30

Associate Professor / Department of Advanced Device Materials / Institute for Materials Chemistry and Engineering


Papers
1. Atsutaka Yamada, Daisuke Izumoto, Tsuyoshi Akiyama, Katsuhiko Fujita, Atsushi Suzuki, Takeo Oku, Insertion effect of spin-coated films of C60-ethylenediamine adduct on organic thin-film solar cells, Irago Conference 2017: A 360-Degree Outlook on Critical Scientific and Technological Challenges for a Sustainable Society The Irago Conference 2017 A 360-Degree Outlook on Critical Scientific and Technological Challenges for a Sustainable Society, 10.1063/1.5021933, 1929, 2018.01, C60-ethylanediamine adduct particle (C60P) were prepared by simply mixing of C60 and ethylenediamine (EDA) in toluene. C60P was dissolved into EDA to obtain C60P-EDA. C60P-EDA can be diluted by ethanol, 2-methoxyethanol or water. Thin films of C60P-EDA were prepared from these diluted solutions of C60P-EDA by spin-coating. Such thin-films were used as a part of organic thin-film solar cells..
2. Yoshinori Kimoto, Kenichi Matsuoka, Katsuhiko Fujita, Lowered work function by solution processable bilayer cathode buffers in inverted organic photovoltaic and parameters of the equivalent circuit, Molecular Crystals and Liquid Crystals, 10.1080/15421406.2017.1358540, 654, 1, 256-262, 2017.09, In this paper, we report solution processable cathode buffers composed polyethyleneimine (PEI) and C60 fullerene or PCBM for OPV. A PEI layer was formed on an ITO surface by dip coating, followed by the immobilization of C60 or PCBM on ITO/PEI surface by the chemical reaction between an aliphatic amine and fullerene. They were used for cathode buffers in OPVs and the device performance was improved compared with the device without the buffer. The improvement can be attributed to the lowered work function (WF) by the dipole formed by PEI and ITO. The parameters in the equivalent circuit with a single diode tells us that the buffers act as electric bilayer lowering the effective voltage on the diode..
3. Shuo Lan, Yoshinori Kimoto, Katsuhiko Fujita, Necessity of interlayer in tandem organic solar cells composed of a bulk heterojunction unit cell and the equivalent circuit, Molecular Crystals and Liquid Crystals, 10.1080/15421406.2017.1358054, 654, 1, 249-255, 2017.09, In an inverted tandem organic solar cell with a bulk heterojunction (BHJ) unit cell, strange s-shape appears in the current-voltage characteristics. We prepared a tandem cell composed of a BHJ bottom unit cell and a p-n stack type top unit cell with an interlayer in between the unit cells. Since the BHJ active layer has symmetric structure, an electron blocking layer is indispensable in the interlayer. The photovoltaic characteristics can be reproduced by an equivalent circuit with an inverted diode between two unit cells. The s-shape can be understood in terms of the reverse rectification by the electron blocking layer..
4. Yoshinori Kimoto, Tsuyoshi Akiyama, Katsuhiko Fujita, Cathode buffer composed of fullerene-ethylenediamine adduct for an organic solar cell, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.7567/JJAP.56.021601, 56, 2, 2017.02, We developed a fullerene-ethylenediamine adduct (C60P-DC) for a cathode buffer material in organic bulk heterojunction solar cells, which enhance the open-circuit voltage (Voc). The evaporative spray deposition using ultra dilute solution (ESDUS) technique was employed to deposit the buffer layer onto the organic active layer to avoid damage during the deposition. By the insertion of a C60P-DC buffer layer, Voc and power conversion efficiency (PCE) were increased from 0.41 to 0.57 V and from 1.65 to 2.10%, respectively. The electron-only device with the C60P-DC buffer showed a much lower current level than that without the buffer, indicating that the Voc increase is caused not by vacuum level shift but by hole blocking. The curve fitting of current density-voltage (J-V) characteristics to the equivalent circuit with a single diode indicated that the decrease in reversed saturation current by hole blocking increased caused the Voc..
5. Kenichi Matsuoka, Ken Albrecht, Kimihisa Yamamoto, Katsuhiko Fujita, Mulifunctional dendritic emitter
Aggregation-induced emission enhanced, thermally activated delayed fluorescent material for solution-processed multilayered organic light-emitting diodes, Scientific Reports, 10.1038/srep41780, 7, 2017.01, Thermally activated delayed fluorescence (TADF) materials emerged as promising light sources in third generation organic light-emitting diodes (OLED). Much effort has been invested for the development of small molecular TADF materials and vacuum process-based efficient TADF-OLEDs. In contrast, a limited number of solution processable high-molecular weight TADF materials toward low cost, large area, and scalable manufacturing of solution processed TADF-OLEDs have been reported so far. In this context, we report benzophenone-core carbazole dendrimers (GnB, n = generation) showing TADF and aggregation-induced emission enhancement (AIEE) properties along with alcohol resistance enabling further solution-based lamination of organic materials. The dendritic structure was found to play an important role for both TADF and AIEE activities in the neat films. By using these multifunctional dendritic emitters as non-doped emissive layers, OLED devices with fully solution processed organic multilayers were successfully fabricated and achieved maximum external quantum efficiency of 5.7%..
6. Ken Albrecht, Kenichi Matsuoka, Daisuke Yokoyama, Yoshiya Sakai, Akira Nakayama, Katsuhiko Fujita, Kimihisa Yamamoto, Thermally activated delayed fluorescence OLEDs with fully solution processed organic layers exhibiting nearly 10% external quantum efficiency, Chemical Communications, 10.1039/c6cc09275f, 53, 16, 2439-2442, 2017.02, New solution processable and laminatable terminally modified carbazole-triazine thermally activated delayed fluorescence (TADF) dendrimers are reported. An OLED device with fully solution processed organic layers exhibited an external quantum efficiency of up to 9.4% at 100 cd m<sup>−2</sup>..
7. Toshinori Matsusima, Takeshi Yasuda, Katsuhiko Fujita, Chihaya Adachi, Field-effect transistors with vacuum-deposited organic-inorganic perovskite films as semiconductor channels, Journal of Applied Physics, 10.1063/1.4972226, 120, 23, 2016.12, Films of the organic-inorganic layered perovskite (C6H5C2H4NH3)2SnI4 were vacuum-deposited on substrates heated at various temperatures (Tsub) to investigate the influence of Tsub on their film quality and transistor performance (hole mobilities, threshold voltages, and current on/off ratios). Appropriate substrate heating at Tsub = 60 °C during vacuum deposition led to better-developed perovskite films with larger grains. These films exhibited the best transistor performance in comparison with films fabricated at the other Tsub. The transistor performance was further enhanced by reducing perovskite semiconductor thickness (t) because of a reduction of bulk resistance in a top-contact/bottom-gate transistor structure. By utilizing the optimized Tsub of 60 °C and t of 31 nm, we obtained the most improved hole mobility of 0.78 ± 0.24 cm2/V s, about 5000 times the hole mobilities of our initial transistors fabricated at Tsub = 24 °C and t = 50 nm..
8. Shin Sakiyama, Naoki Mizutani, Katsuhiko Fujita, Controllable p- and n-type doping of poly[2-methoxy-5-(2'-methyl-hexyloxy)- p-phenylenevinylene] films prepared by evaporative spray deposition using ultradilute solution, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.7567/JJAP.55.04EL03, 55, 4, 2016.04, Evaporative spray deposition using an ultradilute solution (ESDUS) enables polymer film preparation using diluted solution at ppm levels. We used this method for p- and n-type doping of poly[2-methoxy-5-(2'-methyl-hexyloxy)-p-phenylenevinylene] (MEH-PPV), which is a bipolar-transport polymer semiconductor. The device characteristics indicated a drastic improvement of conductivity with carrier mobility. Moreover, the doping efficiency was higher than 15% in both p- and n-type doping owing to the wide dopant dispersion realized by the ESDUS technique..
9. Shin Sakiyama, Takuya Komura, Hirotaka Iwashita, Naoki Mizutani, Katsuhiko Fujita, Carrier density and mobility in n-doped poly(P-phenylene vinylene), Evergreen, 3, 1, 18-20, 2016.01, The conductivity of a polymer semiconductor, poly[2-methoxy-5-(2’-ethylhexyloxy) -p-phenylene vinylene] (MEH-PPV) was drastically improved by n-type doping with LiF. The improvement of the conductivity is mainly caused by the improved carrier mobility. This phenomenon is attributed to trap filling by doping. The carrier generation should take place at a trap level of the semiconductor and the trap level can be filled, resulting in carrier mobility improvement. Furthermore, we fabricated the organic Schottky solar cells with n-doped MEH-PPV. Open circuit voltage (Voc) was significantly increased as the doping concentration increased, indicating that LiF in MEH-PPV can change Fermi level..
10. Tetsuya Kida, Keisuke Horita, Satoshi Suehiro, Masayosh Yuasa, Armando T. Quitain, Tooru Tanaka, Katsuhiko Fujita, Yoichi Ishiwata, Kengo Shimanoe, Influence of Processing Conditions on the Performance of Cu2ZnSnS4 Nanocrystal Solar Cells, ChemistrySelect, 10.1002/slct.201500004, 1, 1, 86-93, 2016.01, Quaternary Cu2ZnSnS4 is a promising solar cell material because of its narrow band gap, high light absorption coefficient, and low cost. It is known that the composition of Cu2ZnSnS4 largely influences the solar cell performance. Here, to study the composition dependent properties of Cu2ZnSnS4 NCs as a solar cell material, we synthesized oleylamine-capped Cu2ZnSnS4 NCs with different compositions by a one-pot solution process, and fabricated solar cells with a ITO/ZnO/CdS/Cu2ZnSnS4/Au structure, and photoelectrochemical cells. A photovoltaic device using Cu2ZnSnS4 NCs with Cu/ (Zn + Sn)=0.87 showed the best performance among the devices tested. To improve the performance, the NC film fabrication processes were modified. We found that ligand stripping with BF3:OEt2 and the subsequent annealing at 250 °C in N2 improved the power conversion efficiency from 0.06 to 0.14 %, most likely due to efficient stripping of surface insulating organic layers. The photocurrent response of a photoelectrochemical cell using the Cu2ZnSnS4 NCs deposited on a ITO substrate was also improved by the modified NC film fabrication processes..
11. Kenichi Matsuoka, Ken Albrecht, Kimihisa Yamamoto, Katsuhiko Fujita, Mono-Substituted carbazole dendrimers as solution processable host materials for phosphorescent organic light-emitting diodes, Journal of Photopolymer Science and Technology, 10.2494/photopolymer.29.323, 29, 2, 323-326, 2016.01.
12. Satoshi Suehiro, Keisuke Horita, Masayoshi Yuasa, Tooru Tanaka, Katsuhiko Fujita, Yoichi Ishiwata, Kengo Shimanoe, Tetsuya Kida, Synthesis of Copper-Antimony-Sulfide Nanocrystals for Solution-Processed Solar Cells, Inorganic Chemistry, 10.1021/acs.inorgchem.5b00858, 54, 16, 7840-7845, 2015.08, The p-type nanocrystals (NCs) of copper-based chalcogenides, such as CuInSe2 and Cu2ZnSnS4, have attracted increasing attention in photovoltaic applications due to their potential to produce cheap solution-processed solar cells. Herein, we report the synthesis of copper-antimony-sulfide (CAS) NCs with different crystal phases including CuSbS2, Cu3SbS4, and Cu12Sb4S13. In addition, their morphology, crystal phase, and optical properties were characterized using transmission electron microscopy, X-ray diffractometry, UV-vis-near-IR spectroscopy, and photoemission yield spectroscopy. The morphology, crystal phase, and electronic structure were significantly dependent on the chemical composition in the CAS system. Devices were fabricated using particulate films consisting of CAS NCs prepared by spin coating without a high-temperature treatment. The CAS NC-based devices exhibited a diode-like current-voltage characteristic when coupled with an n-type CdS layer. In particular, the CuSbS2 NC devices exhibited photovoltaic responses under simulated sunlight, demonstrating its applicability for use in solution-processed solar cells. (Figure Presented)..
13. Albrecht Ken, 松岡 健一, 藤田 克彦, 山元 公寿, Carbazole Dendrimers as Solution-Processable Thermally Activated Delayed-Fluorescence Materials, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201500203, 54, 19, 5677-5682, 2015.05.
14. 松岡 健一, Katsuhiko FUJITA, Modulation of electrochemical property of carbon nanodot by post-chemical reductions, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 10.1016/j.colsurfa.2015.01.034, 470, 15-21, 2015.04.
15. 松岡 健一, Katsuhiko FUJITA, Modulation of electrochemical property of carbon nanodot by post-chemical reductions, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 10.1016/j.colsurfa.2015.01.034, 470, 15-21, 2015.04.
16. Ono, Yuji, 秋山 毅, 番家 翔人, Izumoto, Daisuke, Saito, Jo, 藤田 克彦, Sakaguchi, Hiroshi, Suzuki, Atsushi, 奥  健夫, C-60-ethylenediamine adduct thin film as a buffer layer for inverted-type organic solar cells, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 10.1246/bcsj.20140121, 87, 12, 1335-1342, 2014.12.
17. Katsuhiko FUJITA, Shoto Banya, Tsuyosi Akiyama, Hideyuki Oku, Facile Fabrication and Photovoltaic Application of [60]Fullerene Assembly Films Formed by Reaction between Fullerene and Amines, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 10.1246/bcsj.20140121, 87, 12, 1335-1342, 2014.12.
18. Katsuhiko FUJITA, Dan Wang, Noriaki Yukitake, Anode Buffer for Organic Devices Composed of Gold Nanoparticles Prepared by Ark Plasma Deposition
, Advanced Materials Research, 10.4028, 896, 451-454, 2014.02,

Gold nanoparticles (Au NPs) with mean size of 1 nm were placed on an indium tin oxide (ITO) electrode by ark plasma gun. The hole injection at ITO/organic semiconductor was significantly enhanced by the NPs. Though the hole current was unstable upon the voltage scan, it can be substantially stabilized by the insertion of hyper-branched polystyrene (HPS) thin layer between ITO and Au NPs. The work function of ITO electrode was also increased by NPs. The ITO/HPS/Au NPs structure was applied to the anode of an organic solar cell (OSC) with a bulk heterojunction active layer. The power conversion efficiency was significantly higher than that of OSC without anode buffer layer and almost comparable to that with a representative buffer material.
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19. Suehiro, Satoshi, Horita, Keisuke, Kumamoto, Kota, Katsuhiko FUJITA, Masayoshi Yuasa, Tanaka, Tooru, Kengo Shimanoe, Tetsuya Kida, Solution-Processed Cu2ZnSnS4 Nanocrystal Solar Cells: Efficient Stripping of Surface Insulating Layers Using Alkylating Agents, JOURNAL OF PHYSICAL CHEMISTRY C, 10.1021/jp408360j, 118, 2, 804-810, 2014.01.
20. Yuji Ono, Tsuyoshi Akiyama, Shoto Banya, Daisuke Izumoto, Jo Saito, Katsuhiko Fujita, Hiroshi Sakaguchi, Atsushi Suzuki, Takeo Oku, C60-ethylenediamine adduct thin film as a buffer layer for inverted-type organic solar cells, RSC Advances, 10.1039/c4ra03965c, 4, 66, 34950-34954, 2014.01, Thin films of a C60-ethylenediamine (EDA) adduct were prepared from an EDA solution of the adduct particles. An inverted-type organic thin-film solar cell using the thin film of the C60-EDA adduct as a buffer layer was fabricated. The solar cell performance suggested that the C 60-EDA adduct thin film functioned as an electron-transporting layer, similarly to the titanium oxides in typical inverted-type organic thin-film solar cells..
21. Dan Wang, Noriaki Yukitake, Katsuhiko Fujita, Anode buffer for organic devices composed of gold nanoparticles prepared by arc plasma deposition, 2013 International Conference on Advanced Materials Science and Technology, ICAMST 2013 Advanced Materials Science and Technology - ICAMST 2013, 10.4028/www.scientific.net/AMR.896.451, 896, 451-454, 2014, Gold nanoparticles with mean size of 1 nm were placed on an indium tin oxide (ITO) electrode by arc plasma gun. The hole injection at ITO/organic semiconductor was significantly enhanced. Though the hole current was unstable upon the voltage scan, it can be substantially stabilized by the insertion of hyper-branched polystyrene thin layer between ITO and nanoparticles. The work function of ITO electrode was also increased. The ITO/HPS/gold nanoparticles structure was applied to the anode of an organic solar cell (OSC) with a bulk heterojunction active layer. The power conversion efficiency was significantly higher than that of OSC without anode buffer layer and almost comparable to that with a representative buffer material..
22. Dan Wang, Noriaki Yukitake, Katsuhiko Fujita, Improvement of organic solar cells by anode buffer omposed of evaporated gold nanoparticles, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.7567/JJAP.52.100211, 52, 10 PART1, 2013.10, We here report that evaporated gold islands with mean sizes of 2-3nm can enhance the hole injection at the anode/organic semiconductor in rganic devices. The enhancement was observed only after UV-ozone treatment. It was indicated by elemental analysis that the evaporated gold as partially oxidized by the treatment. The oxidized layer would act as an insulator to increase the work function of the electrode. By inserting a yper-branched polymer, the work function further increased. This method can also be employed in an anode buffer for organic solar cells to mprove the device performance..
23. Dan Wang, Noriaki Yukitake, Katsuhiko FUJITA, Improvement of Organic Solar Cells by Anode Buffer Composed of Evaporated Gold Nanoparticles, Japanese Journal of Applied Physics, 52, 10, 100211, 2013.09, We here report that evaporated gold islands with mean sizes of 2-3 nm can enhance the hole injection at the anode/organic semiconductor in organic devices. The enhancement was observed only after UV-ozone treatment. It was indicated by elemental analysis that the evaporated gold was partially oxidized by the treatment. The oxidized layer would act as an insulator to increase the work function of the electrode. By inserting a hyper-branched polymer, the work function further increased. This method can also be employed in an anode buffer for organic solar cells to improve the device performance. .
24. K. Matsuoka, R. Shibuya, K. Fujita, 「Titration Analysis of Electron Storage and Discharge Properties of Carbon Nanodots」, Chemistry Letters, Vol. 42, No. 2,, pp.156-158 , 2013.02.
25. Tsuyoshi Akiyama, Taiki Ueda, Yuji Ono, Kento Kimura, Ken-ichi Matsuoka,Sunao Yamada, Takeo Oku, Facile Solubilization and Photovoltaic Application of C_60Fullerene -Ethylenediamine Adduct, Chemistry Letters, Vol. 42, No. 2, pp.177-179 , 2013.02.
26. D. Wang,K.Yasui,M.Ozawa,K.Odoi,S.Shimamura,and,K. Fujita (王 丹、安井 圭、小澤 雅昭、大土井 啓祐、島村 槙一、藤田 克彦), 「Hole injection enhancement by sparsely dispersed Au nanoparticles on indium tin oxide electrode in organic light emitting devices」, Applied Physics Letters, Vol.102 , No.2 , 2013.01.
27. Akito Kawanami and Katsuhiko Fujita, Inverted Organic Photovoltaic Cells having Stacked Structure of a Bulk Heterojunction Layer and a Donor Layer, J. Photopol. Sci. Technol., 321-324, 2011.06.
28. Morioka Ryo, Yasui Kei, Ozawa Masaaki, Odoi Keisuke, Ichikawa Hisashi, Fujita Katsuhiko, Anode Buffer Layer containing Au Nanoparticles for High Stability Organic Solar Cells, JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 2010.07.
29. Morioka, R.; Yasui, K.; Ozawa, M.; Odoi, K.; Ichikawa, H.; Fujita, K., Anode buffer layer containing Au nanoparticles for high stability organic solar cells, JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 2010.06.
30. Shakutsui Masato, Iwamoto Tadashi, Fujita Katsuhiko, Bulk-Heterojunction Photovoltaic Cells with Donor-Acceptor Ratio Varied across the Film Prepared by Evaporative Spray Deposition Using Ultradilute Solution Method, JAPANESE JOURNAL OF APPLIED PHYSICS, 49, 6, 060207, 2010.04.
31. Aoki, Y; Shakutsui, M; Fujita, K;, Stacking layered structure of polymer light emitting diodes prepared by evaporative spray deposition using ultradilute solution for improving carrier balance, Thin Solid Films, 518, 493-496, 2009.11.
32. Maeda, R; Iwamoto, T; Shakutsui, M; Fujita, K, Bulk Heterojunction Photovoltaic Cells Prepared by Evaporative Spray Deposition using Ultradilute Solution Technique, JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 22, 4, 525-528, 2009.06.
33. Shakutsui, M; Matsuura, H; Fujita, K,, Improved efficiency of polymer light-emitting diodes by inserting a hole transport layer formed without thermal treatment above glass transition temperature, Organic Electronics, 10, 5, 834-842, 2009.06.
34. Ichikawa, H; Yasui, K; Ozawa, M; Fujita, K, , Electrical bistability of composite film comprising hyper-branched polymer and gold nanoparticle, Synthetic Metals, 159, 9-10, 973-976, 2009.04.
35. Konishi, Misuzu, Fujita, Katsuhiko, Tsutsui, Tetsuo, “Large domain film of bis(styrilanthracene) derivatives prepared by a simple melt-freezing process and the improvement of field effect hole mobility” , JAPANESE JOURNAL OF APPLIED PHYSICS , Volume: 47 Issue: 6 Pages: 4732-4735 , 2008.06.
36. Sagane K, Shakutsui M, Tsutsui T,Fujita K, Polymer field effect transistors of F8T2 prepared by evaporative spray deposition using ultradilute solution technique, JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, Volume: 21 Issue: 2 Pages: 193-196, 2008.06.
37. H.Etori, T.Yasuda, X.L.Jin, K.Fujita, S.Mataka , T.Tsutsui, Design of Multilayer Structures for UV Organic Light-Emitting Diodes Based on 2-(2-Naphthyl)-9,9'-Spirobifluorene , Jpn. J. Appl. Phys., Vol. 46 (No.8A), pp.5071-5075, 2007, 2007.08.
38. R. Maeda, K. Fujita, T. Tsutsui, Improved performance in polymer-fullerene blend photovoltaic cells by insertion of C60 interlayer, Mol. Cryst. Liq. Cryst, Vol.471, pp.23-128, 2007, 2007.08.
39. T.Ashimine, T.Onoue, T.Yasuda, K.Fujita, T.Tsutsui, Parylene-C and High-k Polymer Bilayer Gate Dielectric for Low-Operating Voltage Organic Field-Effect Transistors , Mol. Cryst. Liq. Cryst., Vol.471, pp.221-227, 2007, 2007.08.
40. H.Kayashima, T.Yasuda, K.Fujita, T.Tsutsui, p- and n-Type Charge Transport in Field-Effect Transistors of Pristine Poly(P-Phenylenevinylene), Mater .Res. Soc. Symp. Proc., Vol. 965, pp.0956-S06-11, 2007, 2007.07.
41. M.Shakutsui, K.Fujita, T.Tsutsui , Layered polymer light emitting diode prepared by evaporative spray deposition from ultradilute solution (ESDUS) technique at various substrate temperature, J. Photopolym. Sci. Tech, Vol.20(No.1), pp.53-56, 2007, 2007.07.
42. H.Kayashima, T.Yasuda, K.Fujita, T.Tsutsui, Poly(p-phenylenevinylene)-based field-effect transistor with platinum source-drain electrodes, J. Phys. D: Appl. Phys, Vol.40, pp.1646-1648, 2007, 2007.05.
43. H.Kayashima, T.Yasuda, K.Fujita, T.Tsutsui, Fabrication of p- and n-type Field-Effect Transistors using Poly(p-Phenylenevinylene) via Water-Soluble Precursor under High-Gravity Condition, Jpn. J. Appl. Phys, Vol.46, pp.L177 -L179, 2007, 2007.04.
44. H.Tanaka, T.Yasuda, K.Fujita, T.Tsutsui, Highly-oriented organic thin films and application for photovoltaic device, Mol. Cryst. Liq. Cryst., Vol.462, pp.67-73, 2007, 2007.02.
45. Improvement in Polymer Light-Emitting Diode Performance Using Polymer Heterojunction Structure Prepared by Evaporative Spray Deposition from Ultradilute Solution.
46. H.Tanaka, T.Yasuda, K.Fujita, T.Tsutsui, Transparent Image Sensor Using Organic Multilayer Photodiode, Adv.Mater., Vol.18, pp.2230-2233, 2006, 2006.09.
47. T.Yasuda, T.Goto, K.Fujita, T.Tsutsui, Ambipolar Carrier Transport in Polycrystalline Pentacene Thin Film Transistors, Mole.Cryst.Liq.Cryst., Vol.444, pp.219-224, 2006, 2006.07.
48. H.Tanaka, T.Yasuda, K.Fujita, T.Tsutsui, High Efficiency Polarization-Sensitive Organic Photovoltaic Devices, Appl.Phys.Lett., Vol.88, 253506, 2006 , 2006.06.
49. T.Matsushima, K.Fujita, T.Tsutsui, Preparation of Conductive Organic-Inorganic Cubic Perovskite Thin Films by Dual- Source Vacuum Vapor Deposition, Jpn.J.Appl.Phys., Vol.45, No.1B, pp.523-525, 2006, 2006.05.
50. M. Terai, K. Fujita, T. Tsutsui, Electrical Bistability of Organic Thin-Film Device using Ag Electrode, Jpn.J.Appl.Phys., Vol.45, No.4B, pp.3754-3757, 2006, 2006.05.