Abstract
Photovoltaic properties of BiFeO3 (BFO) and 10 % Mn-doped BFO (BFMO) epitaxial thin-film capacitors using SrRuO3 (SRO) electrodes are investigated. We found that the photovoltaic properties of the BFO capacitors are markedly degraded by the Mn-doping. Incident photon energy dependence of the photovoltaic properties shows that the BFO capacitors exhibit an apparent photovoltaic response even when the incident photon energy is lower than the band gap energy of BFO. This phenomenon is considered to be due to an internal photoemission (IPE) effect, that is, a photoinduced carrier injection from the SRO electrode to the BFO film. The utilization of the IPE effect is suggested to be an effective approach to enhance the photovoltaic properties of the ferroelectric capacitors under visible light illumination.
