ITARU OSAKA

Last Updated :2025/12/02

Affiliations, Positions
Graduate School of Advanced Science and Engineering, Professor
Web Site
E-mail
iosakahiroshima-u.ac.jp
Self-introduction
My research interest includes molecular design and synthesis of functional conjugated polymers, self-assembly, and printable organic thin-film devices such as field-effect transistors and solar cells.

Basic Information

Major Professional Backgrounds

  • 2006/02, 2009/03, Carnegie Mellon University, Department of Chemistry, Postdoctoral Researcher
  • 2009/04/01, 2013/03/31, Hiroshima University, Graduate School of Engineering, Assistant Professor
  • 2013/04, 2016/09, Institute of Physical and Chemical Research
  • 2016/10/01, 2020/03/31, Hiroshima University, Institute of Engineering, Professor
  • 2002/04, 2006/01, Fujifilm, Research Scientist

Educational Backgrounds

  • University of Tsukuba, Japan, 1993/04, 1997/03
  • University of Tsukuba, Japan, 1997/04, 2002/03

Academic Degrees

  • Ph. D, University of Tsukuba

Educational Activity

  • [Bachelor Degree Program] School of Engineering : Cluster 3(Applied Chemistry, Biotechnology and Chemical Engineering) : Program of Applied Chemistry
  • [Master's Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Applied Chemistry Program
  • [Master's Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Smart Innovation Program
  • [Doctoral Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Applied Chemistry Program
  • [Doctoral Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Smart Innovation Program

Research Fields

  • Chemistry;Materials chemistry;Organic and hybrid materials
  • Chemistry;Materials chemistry;Polymer / Textile materials
  • Chemistry;Applied chemistry;Energy-related chemistry
  • Chemistry;Materials chemistry;Device related chemistry

Research Keywords

  • Organic functional materials Conjugated polymers Next generation photovoltaics Printed electronics

Affiliated Academic Societies

  • The Chemical Society of Japan, The Society of Polymer Science Japan, Japan Society of Applied Physics, The Society of Photopolymer Science and Technology, American Chemical Society, Materials Research Society

Educational Activity

Course in Charge

  1. 2025, Liberal Arts Education Program1, 1Term, Carbon-neutral Science and Technology
  2. 2025, Undergraduate Education, 4Term, Basic Organic Chemistry II
  3. 2025, Undergraduate Education, 2Term, Introduction to Fundamental Industry
  4. 2025, Undergraduate Education, 3Term, Synthetic Polymer Chemistry
  5. 2025, Undergraduate Education, Year, Graduation Thesis
  6. 2025, Graduate Education (Master's Program) , 1Term, Special Exercises on Applied Chemistry A
  7. 2025, Graduate Education (Master's Program) , 2Term, Special Exercises on Applied Chemistry A
  8. 2025, Graduate Education (Master's Program) , 3Term, Special Exercises on Applied Chemistry B
  9. 2025, Graduate Education (Master's Program) , 4Term, Special Exercises on Applied Chemistry B
  10. 2025, Graduate Education (Master's Program) , Year, Special Study on Applied Chemistry
  11. 2025, Graduate Education (Master's Program) , 3Term, Advanced Synthetic Polymer Chemistry
  12. 2025, Graduate Education (Doctoral Program) , Year, Special Study on Applied Chemistry
  13. 2025, Graduate Education (Master's Program) , 1Term, Sustainability Materials Science

Research Activities

Academic Papers

  1. Drastic effect of alkylation position in structurally simple benzobisthiazole-terthiophene copolymers on the performance of nonfullerene organic photovoltaics, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 98(8), 202508
  2. Dithienobenzimidazole-based semiconducting polymer for nonfullerene organic photovoltaics, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 98(3), 20250305
  3. Synthesis of indano[60]fullerene thioketone and its application in organic solar cells, BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY, 20, 1270-1277, 20240104
  4. Controlling the Thermoelectric Performance of Doped Naphthobisthiadiazole-Based Donor-Acceptor Conjugated Polymers through Backbone Engineering, ADVANCED SCIENCE, 11(48), 202412
  5. ★, Dithienonaphthobisthiadiazole synthesized by thienannulation of electron-deficient rings: an acceptor building unit for high-performance pi-conjugated polymers, CHEMICAL SCIENCE, 15(47), 19991-20001, 20241204
  6. A highly crystalline face-on pi-conjugated polymer based on alkoxythiophene-flanked benzobisthiazole for organic photovoltaics, POLYMER JOURNAL, 56(11), 1051-1059, 202411
  7. Photon energy loss in ternary polymer solar cells based on nonfullerene acceptor as a third component, BATTERY ENERGY, 3(5), 202409
  8. ★, Efficient Derivatization of a Thienobenzobisthiazole-Based pi-Conjugated Polymer Through Late-Stage Functionalization Towards High-Efficiency Organic Photovoltaic Cells, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 63(47), 20241118
  9. Twisted diphenoquinones fused with thiophene rings: thiophene analogs of bianthrone, CHEMICAL COMMUNICATIONS, 60(75), 10410-10413, 20240916
  10. Manipulating the functionality and structures of pi-conjugated polymers utilizing intramolecular noncovalent interactions towards efficient organic photovoltaics, CHEMICAL SCIENCE, 15(17), 6349-6362, 20240501
  11. Two Isomeric Benzo[d]imidazole-Based Nonfullerene Acceptors for Organic Photovoltaics, ACS APPLIED ENERGY MATERIALS, 7(7), 2946-2954, 20240323
  12. Bending the Rule: Naphthobisthiadiazole-Based Terpolymers with Both High Solubility and Crystallinity for Organic Photovoltaics, ACS APPLIED POLYMER MATERIALS, 6(5), 2586-2593, 20240221
  13. Dependence of Exciton Binding Energy on Bandgap of Organic Semiconductors, JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 14(50), 11412-11420, 20231211
  14. Simple pi-Conjugated Polymers Based on Bithiazole for Nonfullerene Organic Photovoltaics, ACS APPLIED MATERIALS & INTERFACES, 16(3), 3735-3743, 20240109
  15. Employment of Alkoxy Sidechains in Semicrystalline Semiconducting Polymers for Ambient-Stable p-Doped Conjugated Polymers, MACROMOLECULES, 57(1), 328-338, 20231214
  16. Ordered p-conjugated polymer backbone in amorphous blend for high efficiency nonfullerene organic photovoltaics, COMMUNICATIONS MATERIALS, 4(1), 20230921
  17. Microscopic Mechanism of High Efficiency and Stability of Inverted Polymer Fullerene Solar Cells, ACS APPLIED ENERGY MATERIALS, 6(11), 6299-6310, 20230519
  18. Interplay Between pi-Conjugated Polymer Donors and Acceptors Determines Crystalline Order of Their Blends and Photovoltaic Performance, ADVANCED ENERGY MATERIALS, 13(13), 202304
  19. Exciton dynamics of a fused ring pi-conjugated nonfullerene molecule based on dithienonaphthobisthiadiazole, JAPANESE JOURNAL OF APPLIED PHYSICS, 62(SK), 20230801
  20. Naphthobispyrazine bisimide-based semiconducting polymers as electron acceptors for all-polymer photovoltaic cells, POLYMER JOURNAL, 55(4), 443-450, 202304
  21. Halogen-Free p-Conjugated Polymers Based on Thienobenzobisthiazole for Efficient Nonfullerene Organic Solar Cells: Rational Design for Achieving High Backbone Order and High Solubility, ADVANCED SCIENCE, 10(5), 202302
  22. Effect of UV-Light Irradiation on Charge-Accumulation States in PTzBT Polymer Solar Cells, JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 35(3), 193-197, 2022
  23. Synergetic Effect on Enhanced Photovoltaic Performance of Spray-Coated Perovskite Solar Cells Enabled by Additive Doping and Antisolvent Additive Spraying Treatment, ACS APPLIED ENERGY MATERIALS, 5(4), 4149-4158, 20220425
  24. Ester-functionalized quinoxaline-based polymers for application in organic photovoltaics, MATERIALS CHEMISTRY AND PHYSICS, 287, 20220801
  25. Tunable Photoelectric Properties of n-Type Semiconducting Polymer:Small Molecule Blends for Red Light Sensing Phototransistors, ADVANCED OPTICAL MATERIALS, 10(10), 202205
  26. Stability improvement mechanism due to less charge accumulation in ternary polymer solar cells, NPJ FLEXIBLE ELECTRONICS, 6(1), 20220420
  27. Naphthobisthiadiazole-Based pi-Conjugated Polymers for Nonfullerene Solar Cells: Suppressing Intermolecular Interaction Improves Photovoltaic Performance, ACS APPLIED MATERIALS & INTERFACES, 14(12), 14400-14409, 20220330
  28. Naphthobispyrazine Bisimide: A Strong Acceptor Unit for Conjugated Polymers Enabling Highly Coplanar Backbone, Short pi - pi Stacking, and High Electron Transport, CHEMISTRY OF MATERIALS, 34(6), 2717-2729, 20220322
  29. Preparation of (pin)B-B(dan), ORGANIC SYNTHESES, 95, 218-+, 2018
  30. Analyses of Charge Accumulation of PTzBT Ternary Polymer Solar Cells Using ESR Spectroscopy, JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 34(4), 351-356, 2021
  31. Solution Processable Pentafluorophenyl End-Capped Dithienothiophene Organic Semiconductors for Hole-Transporting Organic Field Effect Transistors, ADVANCED ELECTRONIC MATERIALS, 8(3), 202203
  32. Dithiazolylthienothiophene Bisimide: A Novel Electron-Deficient Building Unit for N-Type Semiconducting Polymers, ACS APPLIED MATERIALS & INTERFACES, 11(26), 23410-23416, 20190604
  33. Dithienyl Acenedithiophenediones as New -Extended Quinoidal Cores: Synthesis and Properties, CHEMISTRY-A EUROPEAN JOURNAL, 23(19), 4579-4589, 20170403
  34. Synthesis and Characterization of an Alkoxythiazole-thiazolothiazole Semiconducting Polymer for Organic Solar Cells, ELECTROCHEMISTRY, 85(5), 266-271, 2017
  35. ★, Naphthobischalcogenadiazole Conjugated Polymers: Emerging Materials for Organic Electronics, ADVANCED MATERIALS, 29(25), 1605218, 20170705
  36. Naphthobispyrazine as an Electron-deficient Building Unit for pi-Conjugated Polymers: Efficient Synthesis and Polymer Properties, CHEMISTRY LETTERS, 46(8), 1193-1196, 20170530
  37. Stretchable and waterproof elastomer-coated organic photovoltaics for washable electronic textile applications, NATURE ENERGY, 2(10), 20170918
  38. Impact of side chain placement on thermal stability of solar cells in thiophene-thiazolothiazole polymers, JOURNAL OF MATERIALS CHEMISTRY C, 6(14), 3668-3674, 20180414
  39. ★, Advances in molecular design and synthesis of regioregular polythiophenes, ACCOUNTS OF CHEMICAL RESEARCH, 41(9), 1202-1214, 2008
  40. ★, Efficient inverted polymer solar cells employing favourable molecular orientation, NATURE PHOTONICS, 9(6), 403, 2015
  41. ★, High-efficiency polymer solar cells with small photon energy loss, NATURE COMMUNICATIONS, 6, 10085, 2015
  42. Copper-catalyzed Borylation of Bromoaryl Triflates with Diborons: Chemoselective Replacement of an Ar-Br Bond, CHEMISTRY LETTERS, 47(8), 957-959, 20180609
  43. Nickel and Nucleophilic Cobalt-Catalyzed Trideuteriomethylation of Aryl Halides Using Trideuteriomethyl p-Toluenesulfonate, ORGANIC LETTERS, 20(14), 4375-4378, 20180720
  44. Bimolecular recombination and fill factor in crystalline polymer solar cells, JAPANESE JOURNAL OF APPLIED PHYSICS, 57(8S3), 20080606
  45. Anthranilamide (aam)-substituted diboron: palladium-catalyzed selective B(aam) transfer, CHEMICAL COMMUNICATIONS, 54(67), 9290-9293, 20180828
  46. Correlation between Distribution of Polymer Orientation and Cell Structure in Organic Photovoltaics, ACS APPLIED MATERIALS & INTERFACES, 10(38), 32420-32425, 20180917
  47. Scalable Ultrasonic Spray-Processing Technique for Manufacturing Large-Area CH3NH3PbI3 Perovskite Solar Cells, ACS APPLIED MATERIALS & INTERFACES, 10(44), 38042-38050, 20181107
  48. Durable Ultraflexible Organic Photovoltaics with Novel Metal-Oxide-Free Cathode, ADVANCED FUNCTIONAL MATERIALS, 29(6), 201902
  49. Anthranilamide (aam)-substituted arylboranes in direct carbon-carbon bond-forming reactions, CHEMICAL COMMUNICATIONS, 55(18), 2624-2627, 20190304
  50. A Thiazolothiazole-Based Semiconducting Polymer with Well-Balanced Hole and Electron Mobilities, APPLIED SCIENCES, 9(3), 20190129
  51. Ni/Co-Catalyzed Homo-Coupling of Alkyl Tosylates, MOLECULES, 24(8), 20190402
  52. An anthranilamide-substituted borane [H-B(aam)]: its stability and application to iridium-catalyzed stereoselective hydroboration of alkynes, CHEMICAL COMMUNICATIONS, 55(38), 5420-5422, 20190511
  53. Ester-Functionalized Naphthobispyrazine as an Acceptor Building Unit for Semiconducting Polymers: Synthesis, Properties, and Photovoltaic Performance, MACROMOLECULES, 52(10), 3909-3917, 20190514
  54. High Operation Stability of Ultraflexible Organic Solar Cells with Ultraviolet-Filtering Substrates, ADVANCED MATERIALS, 31(19), 20190510
  55. Copper-catalyzed arylstannylation of arynes in a sequence, CHEMICAL COMMUNICATIONS, 55(46), 6503-6506, 20190611
  56. Copper-Catalyzed B(dan)-Installing Allylic Borylation of Allylic Phosphates, ADVANCED SYNTHESIS & CATALYSIS, 361(10), 2286-2290, 20190514
  57. ★, Impact of Isomeric Structures on Transistor Performances in Naphthodithiophene Semiconducting Polymers, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 133, 6852-6860, 2011
  58. ★, Drastic Change of Molecular Orientation in a Thiazolothiazole Copolymer by Molecular-Weight Control and Blending with PC61BM Leads to High Efficiencies in Solar Cells, ADVANCED MATERIALS, 24, 425-430, 2012
  59. ★, Synthesis, Characterization, and Transistor and Solar Cell Applications of a Naphthobisthiadiazole-Based Semiconducting Polymer, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 134, 3498-3507, 2012
  60. ★, Naphthodithiophene-Naphthobisthiadiazole Copolymers for Solar Cells: Alkylation Drives the Polymer Backbone Flat and Promotes Efficiency, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 135, 8834-8837, 2013
  61. ★, Thiophene–Thiazolothiazole Copolymers: Significant Impact of Side Chain Composition on Backbone Orientation and Solar Cell Performances, ADVANCED MATERIALS, 26, 331-338, 2014
  62. ★, Implication of Fluorine Atom on Electronic Properties, Ordering Structures, and Photovoltaic Performance in Naphthobisthiadiazole- Based Semiconducting Polymers, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 138, 10265-10275, 2016
  63. Understanding Comparable Charge Transport Between Edge-on and Face-on Polymers in a Thiazolothiazole Polymer System, ACS APPLIED POLYMER MATERIALS, 1(6), 1257-1262, 20190429
  64. One-pot Sequential Fluorostannylation-Arylstannylation of Arynes, CHEMISTRY LETTERS, 48(9), 1032-1034, 201909
  65. Synthesis and Deformable Hierarchical Nanostructure of Intrinsically Stretchable ABA Triblock Copolymer Composed of Poly(3-hexylthiophene) and Polyisobutylene Segments, ACS APPLIED POLYMER MATERIALS, 1(3), 315-320, 201903
  66. Ultrasonic Spray-Coated Mixed Cation Perovskite Films and Solar Cells, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, 7(16), 14217-14224, 20190819
  67. Nickel/Cobalt-Catalyzed C(sp(3))-C(sp(3)) Cross-Coupling of Alkyl Halides with Alkyl Tosylates, ACS CATALYSIS, 9(10), 9285-9291, 201910
  68. Direct Suzuki-Miyaura Coupling with Naphthalene-1,8-diaminato (dan)-Substituted Organoborons, ACS CATALYSIS, 10(1), 346-351, 20200103
  69. Mixed-Ligand Approach to Palladium-Catalyzed Direct Arylation Polymerization: Synthesis of Donor-Acceptor Polymers Containing Unsubstituted Bithiophene Units, MACROMOLECULES, 53(1), 158-164, 20200114
  70. Reductive amidation of alkyl tosylates with isocyanates by a Ni/Co-dual catalytic system, CHEMICAL COMMUNICATIONS, 56(8), 1247-1250, 20200125
  71. ★, Impact of Noncovalent Sulfur-Fluorine Interaction Position on Properties, Structures, and Photovoltaic Performance in Naphthobisthiadiazole-Based Semiconducting Polymers, ADVANCED ENERGY MATERIALS, 10(7), 202002
  72. Direct Evidence of Less Charge Accumulation in Highly Durable Polymer Solar Cells Using Operando Electron Spin Resonance Spectroscopy, ACS APPLIED ENERGY MATERIALS, 3(2), 2028-2036, 202002
  73. Semiconducting small molecule/polymer blends for organic transistors, POLYMER, 191, 20200316
  74. Dithiazolylthienothiophene Bisimide-Based pi-Conjugated Polymers: Improved Synthesis and Application to Organic Photovoltaics as P-Type Semiconductor, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 93(4), 561-567, 202002
  75. Sequential Ultrasonic Spray-Coating Planar Three Layers for 1 cm(2) Active Area Inverted Perovskite Solar Cells, ENERGY TECHNOLOGY, 8(7), 202007
  76. Effect of Spacer Length in Naphthobispyrazine-Based pi-Conjugated Polymers on Properties, Thin Film Structures, and Photovoltaic Performances, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 93(8), 949-957, 202005
  77. pi-Conjugated polymers and molecules enabling small photon energy loss simultaneously with high efficiency in organic photovoltaics, JOURNAL OF MATERIALS CHEMISTRY A, 8(39), 20213-20237, 20201021
  78. Small-bandgap quinoid-based p-conjugated polymers, JOURNAL OF MATERIALS CHEMISTRY C, 8(41), 14262-14288, 20201107
  79. Significantly Sensitized Ternary Blend Polymer Solar Cells with a Very Small Content of the Narrow-Band Gap Third Component That Utilizes Optical Interference, MACROMOLECULES, 53(23), 10623-10635, 20201208
  80. Visible light-driven Giese reaction with alkyl tosylates catalysed by nucleophilic cobalt, RSC ADVANCES, 11(6), 3539-3546, 20210127
  81. Controlled steric selectivity in molecular doping towards closest-packed supramolecular conductors, COMMUNICATIONS MATERIALS, 1(1), 20201104
  82. Multi-Channel Pumped Ultrasonic Spray-Coating for High-Throughput and Scalable Mixed Halide Perovskite Solar Cells, ADVANCED MATERIALS INTERFACES, 8(5), 202103
  83. Donor-Acceptor Polymers Containing 4,8-Dithienylbenzo[1,2-b:4,5-b ']dithiophene via Highly Selective Direct Arylation Polymerization, ACS APPLIED POLYMER MATERIALS, 3(2), 830-836, 20210212
  84. Analyses of PTzNTz Polymer Solar Cells Using ESR Spectroscopy, JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 33(1), 97-102, 2020
  85. Spray deposition of NiOx hole transport layer and perovskite photoabsorber in fabrication of photovoltaic mini-module, JOURNAL OF POWER SOURCES, 491, 20210415
  86. N-type Semiconducting Polymers Based on Dicyano Naphthobisthiadiazole: High Electron Mobility with Unfavorable Backbone Twist, CHEMISTRY OF MATERIALS, 33(6), 2218-2228, 20210323
  87. Self-powered ultraflexible photonic skin for continuous bio-signal detection via air-operation-stable polymer light-emitting diodes, NATURE COMMUNICATIONS, 12(1), 20210414
  88. Bithiazole Dicarboxylate Ester: An Easily Accessible Electron-Deficient Building Unit for pi-Conjugated Polymers Enabling Electron Transport, MACROMOLECULES, 54(7), 3489-3497, 20210413
  89. One-Step Spray-Coated All-Inorganic CsPbI2Br Perovskite Solar Cells, ACS APPLIED ENERGY MATERIALS, 4(6), 5466-5474, 20210628
  90. Molecular Understanding of How the Interfacial Structure Impacts the Open-Circuit Voltage of Highly Crystalline Polymer Solar Cells, ACS APPLIED MATERIALS & INTERFACES, 13(29), 34357-34366, 20210728
  91. Effect of Ester Side Chains on Photovoltaic Performance in Thiophene-Thiazolothiazole Copolymers, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 94(8), 2019-2027, 202108
  92. Extended pi-Electron Delocalization in Quinoid-Based Conjugated Polymers Boosts Intrachain Charge Carrier Transport, CHEMISTRY OF MATERIALS, 33(21), 8183-8193, 20211109
  93. Contrasting Effect of Side-Chain Placement on Photovoltaic Performance of Binary and Ternary Blend Organic Solar Cells in Benzodithiophene-Thiazolothiazole Polymers, CHEMSUSCHEM, 14(22), 5032-5041, 20211119
  94. Pronounced Backbone Coplanarization by p-Extension in a Sterically Hindered Conjugated Polymer System Leads to Higher Photovoltaic Performance in Non-Fullerene Solar Cells, ACS APPLIED MATERIALS & INTERFACES, 13(47), 56420-56429, 20211201

Awards

  1. 2013, SPSJ Hitachi Award, Society of Polymer Science Japan, 縮環π電子系縮環π電子系を基盤とする高性能半導体ポリマーの開発

External Funds

Acceptance Results of Competitive Funds

  1. NEDO Feasibility Study Program, 2021/05, 2023/03
  2. Strategic Basic Research Programs(CREST), 2021/04/01, 2023/03/31
  3. JST-Mirai Program, 2020/11/01, 2024/03/31
  4. Strategic Basic Research Programs(ALCA), 2016/10/01, 2019/03/31
  5. KAKENHI(Grant-in-Aid for Scientific Research (B)), 2016, 2018
  6. JST-Mirai Program, 2020/11/01, 2023/03/31