Formation and application of nanocluster-assembled materials composed of carbon- and metal-oxide-nanoclusters

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02463
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26040:Structural materials and functional materials-related
• Research Institution: Nagoya University
• Principal Investigator: Nakaya Masato 名古屋大学, 工学研究科, 准教授 (30725156)
• Project Period (FY): 2020-04-01 – 2023-03-31
• 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 / ナノクラスター / フラーレン / 金属酸化物

Outline of Final Research Achievements

High performance flexible thermoelectric (TE) conversion devices have been expected to be power sources for enormous number of wearable sensors for future internet-of-things (IoT). Although the fullerene C60 film is one of candidates of novel flexible TE materials because of its giant Seebeck coefficient (S > 100 mV/K) at room temperature, improvement of its very low electrical conductivity (σ < 10-6 /Ωcm) 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 conventional materials.
In this research project, it has been demonstrated for the first time that the novel high performance TE thin film was created by assembly from C60 molecules and molybdenum trioxide nanoclusters. This nanocluster-assembled thin film exhibited excellent thermoelectric power factor that is 100 times larger than that of C60 film.

Free Research Field

ナノサイエンス、ナノ計測、ナノ物質科学、環境発電

Academic Significance and Societal Importance of the Research Achievements

炭素ナノクラスター（C60）と三酸化モリブデンナノクラスターから構成されるナノクラスター集積固体薄膜の開発に世界で初めて成功した。このナノクラスター固体は、主構成要素であるC60薄膜と同等の巨大ゼーベック係数を示しつつ1000倍大きな導電性を有するのでC60薄膜に比べて約100倍大きな出力因子を示すことが明らかになった。この複合薄膜では、組成比や加熱処理温度を調整することでゼーベック係数、導電率およびP型／N型特性を制御可能であるので実用的なπ型熱電変換素子への応用にも適しており、近未来のIoT社会を支える人体装着型ワイヤレス電源の実現に資することが期待される。