Influence of the polarization direction of light on the anomalous photovoltaic effect in BiFeO3 thin films

Recently, an anomalous photovoltaic effect in a BiFeO3 (BFO) thin film has attracted much attention. In this research, Pt/BFO/Pt coplanar capacitors have been prepared using striped- and single-domain structured BFO thin films, and the influence of the polarization direction of incident violet laser light (λ = 405 nm) on the photovoltage of these capacitors has been investigated. In a specific geometry, both coplanar capacitors, the one using a striped-domain and the other using a single-domain structured BFO thin film showed anomalous photovoltages above band gap of BFO, indicating that an anomalous photovoltage should be observed under randomly-polarized light illumination such as that by a halogen lamp.