Abstract
Nowadays,photovoltaic effect has been widely studied in various ferroelectric materials due to its ap-plications as optoelectronic devices.In this work,with BiFeO3(BFO)films as the photovoltaic materials,we report the effects of Eu3+doping content on the phase structure,ferroelectric and optical properties of BFO films grown on Ca0.96Ce0.04MnO3/YAlO3(001)substrate.We found that a small doping level of 0.05 could induce a phase change of BFO from tetragonal to rhombohedral,due to the shrinking of the lattice upon Eu3+doping and the breaking of surface terrace structure induced by Ca0.96Ce0.04Mn03 layer.This results in a sharp band gap reduction from 3.30 eV to 2.60 eV,and a decrease in the coercivity of ferroelectric polarization switching.Based on these findings,we investigate the photovoltaic effects of ITO/EuxBi1-xFeO3/Ca0.96Ce0.04MnO3 vertical capacitors.It is found that the short-circuit current density(Jsc)decreases with increasing Eu3+doping,whereas the open-circuit voltage(Voc)first increases to a level of 0.1 V and then decreases with further Eu3+doping.This could be explained by the combined ef-fect of Schottky-junction and depolarization field on the photovoltaic process.Our research suggests that a moderate Eu3+doping is helpful for enhancing the photovoltaic effect of BFO thin film devices.
基金项目
National Natural Science Foun-dation of China(61974147)
National Natural Science Foun-dation of China(52031014)
NETL
NSTL
万方数据