2019 Fiscal Year Final Research Report
Development of novel electronic properties of organic semiconductor thin films by field-effect doping and their characterization
| Project/Area Number |
17K05506
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics I
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| Research Institution | Toyota Physical and Chemical Research Institute |
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Principal Investigator |
Kuroda Shin-ichi 公益財団法人豊田理化学研究所, フェロー事業部門, フェロー (20291403)
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| Co-Investigator(Kenkyū-buntansha) |
伊東 裕 名古屋大学, 工学研究科, 准教授 (10260374)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | キャリアドーピング / 有機半導体 / 電子スピン共鳴 / 波動関数 / DFT計算 / 導電性高分子 / 絶縁体－金属転移 |
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| Outline of Final Research Achievements |
By using electron spin resonance (ESR) together with conduction measurements, the electronic states and conduction mechanism of the organic semiconductor materials were investigated mainly by probing the field-induced charge carriers in the transistor structures of the thienothiophene-based high-mobility organic semiconductors. In particular, for the typical molecular semiconductor based on C8-BTBT having alkyl side chains, the spatial extent of the carrier wave function over 100 molecules was clarified for the first time from the observed hyperfine-determined ESR linewidth. The observed large extent microscopically supports the band-like transport mechanism and is consistent with the high crystalline order of the system. In PBTTT, a high-mobility polymer material, the evolution of the metallic state due to high carrier injection by ionic liquid was confirmed from the dc conductivity and magnetoresistance measurements.
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| Free Research Field |
固体物性、磁気共鳴、有機エレクトロニクス
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| Academic Significance and Societal Importance of the Research Achievements |
有機半導体は有機トランジスタなどのフレキシブルな薄膜デバイスの素材として注目される。移動度などの性能向上には有機半導体中のキャリアのミクロなレベルでの理解が不可欠である。本研究でのESR法により、チエノチオフェン系分子性半導体でのキャリア波動関数の広がりが、従来の材料よりも格段に大きくバンド的伝導性と良く符合することを示した結果は、平面性の高いチエノチオフェン核とアルキル鎖を効果的に組み合わせた分子構造が高移動度材料の設計指針として有効なことを示し、大きな波及効果をもつ。また、チエノチオフェン系高分子半導体の高濃度ドーピングでは良好な金属特性を発現することも示し熱電材料の開発にも寄与している。
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