Development of new field-effect device with ionic liquid gating

2015 Fiscal Year Final Research Report

• Project/Area Number: 25708039
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Device related chemistry
• Research Institution: The University of Tokyo
• Principal Investigator: UENO Kazunori 東京大学, 総合文化研究科, 准教授 (10396509)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 電気二重層トランジスタ / モットトランジスタ / イオン液体 / 強相関電子系 / 遷移金属酸化物 / 金属絶縁体転移

Outline of Final Research Achievements

Metal-insulator transition was electrostatically tuned in a strongly correlated electron system, SrVO3 ultra-thin film with an electric double layer configuration with an ionic liquid electrolyte. The device worked as a Mott transistor. Although a SrVO3 bulk single crystal is a good metal, a ultra-thin film with a thickness less than 10 mono-layer is a Mott insulator due to low dimensionality. We found that an insulating film showed insulator-to-metal transition by n-type doping. In addition, we also found that a thicker film with metallic conduction showed a transition from metal to insulator with the same n-type doping. We examined gate induced metal-insulator transition in films with various thickness, and draw a electronic phase diagram of the two dimensional Mott insulator SrVO3. The phase diagram has large insulator area and narrow metallic area around n = 1, contrasting to a conventional Mott insulator phase diagram with a narrow insulator area in a large metallic area.

Free Research Field

固体物理学