Control of surface electronic states for anatase TiO2 thin film by interface engineering

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K17470
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Minohara Makoto 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 特別助教 (70728633)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 酸化物表面・界面

Outline of Final Research Achievements

We have investigated the electronic structure of polar/nonpolar oxide heterointerfaces between (001)-oriented LaFeO3 film and Nb:SrTiO3 substrate with different interfacial termination layer using x-ray photoemission spectroscopy. A certain built-in potential forms in Nb:SrTiO3 substrate for the LaFeO3/SrO-Nb:SrTiO3, while almost flat band is maintained even after the LaFeO3 deposition for the LaFeO3/TiO2-Nb:SrTiO3. Since the estimated charge in the depletion layer is not sufficient to solve the polarity mismatch, the electronic reconstruction are presumably occurred in both sides of the LaFeO3 film and the Nb:SrTiO3 substrate. Moreover, the valence band spectra of thick LaFeO3 films rigidly shifts ~0.4 eV by changing the interfacial termination layer. This result indicates the different internal potential formation in LaFeO3 film depending on the interfacial polarity, supporting the abovementioned interpretation on the possible electric reconstruction in LaFeO3 layer.

Free Research Field

酸化物エレクトロニクス