Studies of the switchable photovoltaic effect in co-substituted BiFeO3 thin films

We report the photovoltaic properties of doped ferroelectric [Bi0.9La0.1][Fe0.97Ti0.02Zr0.01]O-3 (BLFTZO) thin films. Polycrystalline BLFTZO films were fabricated on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition technique. Al-doped ZnO transparent top electrodes complete the ZnO:Al/BLFTZO/Pt metal-ferroelectric-metal capacitor structures. BLFTZO showed switchable photoresponse in both polarities. The open circuit voltage (V-OC) and short circuit current (J(SC)) were found to be similar to 0.022V and similar to 650 mu A/cm(2), respectively after positive poling, whereas significant difference in V-OC similar to 0.018V and J(SC) similar to 700 mu A/cm(2) was observed after negative poling. The observed switchable photocurrent and photovoltage responses are explained on the basis of polarization flipping in BLFTZO due to the applied poling field. (C) 2014 AIP Publishing LLC.