Electric field accumulation and giant thermopower modulation of one dimensional electron gas in oxide semiconductors

2016 Fiscal Year Final Research Report

• Project/Area Number: 25246023
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Hokkaido University
• Principal Investigator: Ohta Hiromichi 北海道大学, 電子科学研究所, 教授 (80372530)
• Research Collaborator: KATASE TAKAYOSHI 北海道大学, 電子科学研究所, 助教 (90648388)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 含水ナノ多孔性ガラス / 熱電能 / 一次元電子ガス / AFMリソグラフィー / 光・電気・磁気特性の可逆変調

Outline of Final Research Achievements

In this study, I targeted electric field accumulation and observation of giant thermopower of one dimensional electron gas (1DEG) by AFM lithography technique utilizing an electrochemical redox reaction between H+/OH- ions in the nanoporous glass and oxide semiconductors. Although I succeeded AFM lithography of SrTiO3-1DEG since the resultant shape suggested 1DEG formation, the thermopower could not be measured due to the low stability of the resultant 1DEG. Therefore, I searched more appropriate materials, which show stable redox reaction. As a result, I observed several stable reversible redox reactions such as insulating VO2 - metal HxVO2, insulating SrCoO2.5 - metal SrCoO3, and insulating WO3 - metal HWO3 by using H+/OH- ions in the nanoporous glass. These results appeared on Journal papers, newspapers, and TV. Unfortunately 1DEG has not been realized in this study duration, I think that 1DEG can be realized by AFM lithography of the above materials near future.

Free Research Field

材料科学