Switchable photovoltaic response from polarization modulated interfaces in BiFeO3 thin films

Abstract

Oxygen vacancies induced switchable and nonswitchable photovoltaic effects in Ag/Bi0.9La0.1FeO3 /La0.7Sr0.3MnO3 sandwiched capacitors Appl. Phys. Lett.The switchable photovoltaic effect in BiFeO 3 thin films capacitors has been studied extensively. However, the origin of the photovoltaic response is still under debate. Both bulk depolarization field and interface effects have been used to explain the observations. In this work, we fabricate BiFeO 3 epitaxial films on SrTiO 3 substrate with La 0.7 Sr 0.3 MnO 3 and Pt as electrodes. Much larger switchable photovoltaic response can be observed in the Pt/BiFeO 3 /La 0.7 Sr 0.3 MnO 3 samples, as compared with La 0.7 Sr 0.3 MnO 3 /BiFeO 3 /La 0.7 Sr 0.3 MnO 3 . Moreover, the photovoltaic voltage of the Pt/BiFeO 3 /La 0.7 Sr 0.3 MnO 3 samples is nearly independent of the thickness of the La 0.7 Sr 0.3 MnO 3 bottom electrode. We suggest that the Schottky barrier modulation by ferroelectric polarization at the Pt/BiFeO 3 interface is mainly responsible for the photovoltaic effect, with very small contribution from the bulk depolarization field. V C 2014 AIP Publishing LLC. [http://dx.

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Enhanced photovoltaic effects and switchable conduction behavior in BiFe0.6Sc0.4O3 thin films

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