Thermal conductivity switching by electric-field induced 2D-3D structural phase transition

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K18881
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Katase Takayoshi 東京工業大学, 元素戦略MDX研究センター, 准教授 (90648388)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 熱伝導率 / 薄膜トランジスタ / 構造転移

Outline of Final Research Achievements

Electric-field induced transition between two-dimensional (2D) and three-dimensional (3D) structures was demonstrated in epitaxial thin films of nonequilibrium (Pb1-xSnx)Se solid solution to develop thermal conductivity switching devices with giant electrical conductivity and lattice thermal conductivity change. Giant modulation in electronic conductivity at 7 orders of magnitude was demonstrated in (Pb1-xSnx)Se films by reversible 2D-3D structural transition, where the transition temperature was modulated by changing x values. In addition, electric double-layer transistors using (Pb1-xSnx)Se thin films as active layers were fabricated, and the 2D-3D structural transition was controlled by the application of negative gate bias, resulting in a reversible control of the sheet resistance by more than two orders of magnitude.

Free Research Field

材料科学

Academic Significance and Societal Importance of the Research Achievements

膨大な未利用熱の効果的な削減・有効利用に向けて、外場により固体の熱伝導率を大きく制御可能なデバイスの開発が求められている。本研究では、当研究グループ独自の「2次元(2D)－3次元(3D)構造転移材料(Pb1-xSnx)Se」のエピタキシャル薄膜を用いて、電場印加による結晶構造の次元性と電気抵抗の可逆制御が可能なデバイスを実証した。開発したデバイスを応用することで熱伝導率を大きく制御可能な熱スイッチ素子の実現に繋がると期待できる。