The enhanced photocurrent of epitaxial BiFeO3 film at 130 °C

The short-circuit photocurrent (ISC) that can be reversed by polarization switch enhances with temperature increasing to 130 °C in the epitaxial BiFeO3 thin film on SrTiO3 substrate. The La2/3Sr1/3MnO3/BiFeO3/indium tin oxide (In2O3:SnO2 = 9:1) junction shows the current rectifying characteristic and the photovoltaic effect at 20–130 °C. Importantly, the ISC can be reversed by the polarization switch in this temperature range. More charge carriers are activated and the density of free electrons enhances with the increase in the temperature, which results in the decrease in the depletion layer width. As a result, the open-circuit voltage decreases 50% and the ISC increases from 180 nA to 404 nA with the increase in the temperature from 20 °C to 130 °C. This suggests that the corresponding sensors and devices can be used at a relatively high temperature.