Farbrication of polar superstructures to develop new photovoltaic materials

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H05426
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Nakamura Masao 国立研究開発法人理化学研究所, 創発物性科学研究センター, 上級研究員 (50525780)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 酸化物ヘテロ界面 / 自発分極 / バルク光起電力効果 / 太陽電池

Outline of Final Research Achievements

The bulk photovoltaic effect observed in polar materials has a potential to be a photon-to-electron conversion mechanism to realize novel high efficiency solar cells. In this study, I investigated photovoltaic properties of heterojunctions composed of LaFeO3 and SrTiO3. Due to the polar discontinuity at the interface, the originally nonpolar insulator LaFeO3 becomes polar. The junctions exhibit anomalous photovoltaic properties driven by the induced polarization, such as the reversal of the sign of photocurrent depending on the thickness and interfacial termination layer. The photovoltaic efficiency of the LaFeO3 junctions exhibits large improvement compared to other Mott insulator junctions due to the bulk photovoltaic effect associated with the induced polarization.

Free Research Field

薄膜界面の光機能性