Suggestion of Strategy for Development of Thermoelectric Nanomaterials Based on the Kubo-Luttinger Theory

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15117
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 28020:Nanostructural physics-related
• Research Institution: Tokyo University of Science
• Principal Investigator: Matsubara Manaho 東京理科大学, 理学部第一部物理学科, 助教 (20867832)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: カーボンナノチューブ / グラフェン / FeSe / 熱電変換 / パワーファクター / ゼーベック係数

Outline of Final Research Achievements

This study proposed design concepts to improve thermoelectric properties of low-dimensional thermoelectric materials using the Kubo-Luttinger theory. (1) We predicted the optimal nitrogen concentration that maximizes the power factor (PF) of nitrogen-doped carbon nanotubes and found that the maximum PF value increases as the carbon nanotube diameter decreases. (2) We also found that applying a perpendicular electric field to a bilayer graphene significantly enhances the PF near the band edge. (3) Finally, we suggested that if the bands are degenerate at the Fermi level, both large electrical conductivity and large Seebeck coefficient can be achieved by splitting the degeneracy of the electronic states by applying an external electric field, for example.

Free Research Field

計算物質科学

Academic Significance and Societal Importance of the Research Achievements

身の回りのあらゆるものがインターネットと繋がるIoT社会において，熱から電気を得る熱電変換材料の研究は，以前にも増して重要となっている．本研究では，熱電性能を高精度に評価することができる久保・ラッティンジャーの理論を用いて，低次元材料の熱電性能を最適化するための定量的な指針を示した．さらに，大きな電気伝導率とゼーベック係数を実現するための新たな熱電材料開発のコンセプトも提案した．これらの成果は実践的かつ汎用的であり，今後の熱電材料開発やデバイス応用への貢献が期待される．