Thin-film transistors composed of rare-earth hydride semiconductors and their 1S-band superconductivity

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04583
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Okayama University of Science
• Principal Investigator: Nakamura Osamu 岡山理科大学, 研究・社会連携センター, 教授 (60749315)
• Co-Investigator(Kenkyū-buntansha): 花尻 達郎 東洋大学, 理工学部, 教授 (30266994) ; 酒井 政道 埼玉大学, 理工学研究科, 教授 (40192588)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 希土類 / 水素 / 薄膜 / トランジスタ

Outline of Final Research Achievements

Among the rare-earth hydrides, we focused on YbH2 (and YH3), for which there were insufficient data on resistivity and optical yields. Our hydride preparation method consisted of a Pt catalyst layer (4-5 nm)/Yb film (40 nm-300 nm) with a YbH2 film formed in a hydrogen atmosphere. For this purpose, we established the preparation conditions of YbH2 and the method of removing the Pt layer. Optical measurements of the YbH2 films were performed and correlated with band calculations. The electronic state near the Fermi level was clarified, and the operation of YH3 was not stabilized due to hydrogen desorption and so on. Therefore, we focused on YbH2 and tried to make a transistor. However, no transistor operation was achieved.

Free Research Field

強相関電子系

Academic Significance and Societal Importance of the Research Achievements

この研究の目的は、希土類水素化物半導体の価電子帯(1sバンド)のホール伝導をみるために実現し、希土類水素化物半導体の薄膜トランジスタを作成して、ゲート電極にマイナス電圧を印加してチャネル層にホールを誘起してCorrelated Transfer効果(J. E. Hirsh, Phys. Rev. B 48 (1993)3327)による超伝導を実現することにあった。
しかしながら、動作するTFT試作に至らず、目的を達成していない。しかしながら、YbH2の光学データの面では、学術的に貢献できたと考えている。