2020 Fiscal Year Final Research Report
Formation of high-performance thermoelectric materials by control of intermolecular chemical bonds between functional molecules
Project/Area Number |
19K22049
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Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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Allocation Type | Multi-year Fund |
Review Section |
Medium-sized Section 26:Materials engineering and related fields
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Research Institution | Nagoya University |
Principal Investigator |
Nakaya Masato 名古屋大学, 工学研究科, 准教授 (30725156)
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Project Period (FY) |
2019-06-28 – 2021-03-31
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Keywords | エネルギーハーベスティング / 熱電変換 / ゼーベック効果 / 有機材料 / フラーレン / 重合反応 / 有機薄膜 / ウェアラブルデバイス |
Outline of Final Research Achievements |
High performance and flexible thermoelectric (TE) conversion devices are expected to be power sources for enormous number of wearable devices for future Internet-of-Things (IoT). Although a fullerene C60 film is one of candidates of novel flexible TE materials because of its giant Seebeck coefficient (S > 100 mv/K) at around room temperature, improvement of its very low electrical conductivity (σ: ~10-5 Ω-1cm-1) is required for practical use. However, it is generally difficult to realize TE materials exhibiting large values of both S and σ simultaneously owing to the trade-off relationship between them in bulk materials. In this research project, I demonstrated that the σ is improved with maintaining a giant S for the C60 film by formation of intermolecular covalent bonds between adjacent C60 molecules. This is the novel methodology for control of TE property of organic semiconductors.
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Free Research Field |
ナノサイエンス、ナノ計測、ナノ物質科学、ナノエレクトロニクス
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Academic Significance and Societal Importance of the Research Achievements |
有機半導体の示す巨大ゼーベック係数S(S > 数10 mV/K)を保持しつつ、導電率σを向上させることができれば、柔らかく高性能な熱電素子への応用が拓かれる。分子薄膜のσを向上させる手法としては、不純物添加によるキャリアドープがより一般的であるものの、この方法では、σの増加と共にS値の著しい減少が起きる。本研究では、分子間結合の形成によって、分子薄膜の巨大Sを保持しながらσを向上させることに初めて成功した。この方法論を様々な有機半導体へ応用することでSとσが共に優れた値を示す高性能熱電材料の創製へと道が拓かれる。
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