Switchable photovoltaic response from polarization modulated interfaces in BiFeO3 thin films

The switchable photovoltaic effect in BiFeO3 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 BiFeO3...

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Bibliographic Details
Main Authors: Fang, Liang, You, Lu, Zhou, Yang, Ren, Peng, Lim, Zhi Shiuh, Wang, Junling
Other Authors: School of Materials Science & Engineering
Format: Article
Language:English
Published: 2014
Subjects:
Online Access:https://hdl.handle.net/10356/104104
http://hdl.handle.net/10220/19550
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Institution: Nanyang Technological University
Language: English
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Summary:The switchable photovoltaic effect in BiFeO3 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 BiFeO3 epitaxial films on SrTiO3 substrate with La0.7Sr0.3MnO3 and Pt as electrodes. Much larger switchable photovoltaic response can be observed in the Pt/BiFeO3/La0.7Sr0.3MnO3 samples, as compared with La0.7Sr0.3MnO3/BiFeO3/La0.7Sr0.3MnO3. Moreover, the photovoltaic voltage of the Pt/BiFeO3/La0.7Sr0.3MnO3 samples is nearly independent of the thickness of the La0.7Sr0.3MnO3 bottom electrode. We suggest that the Schottky barrier modulation by ferroelectric polarization at the Pt/BiFeO3 interface is mainly responsible for the photovoltaic effect, with very small contribution from the bulk depolarization field.