Switchable charge-transfer in the photoelectrochemical energy-conversion process of ferroelectric BiFeO₃ photoelectrodes

Instead of conventional semiconductor photoelectrodes herein we focus on BiFeO₃ ferroelectric photoelectrodes to break the limits imposed by common semiconductors. As a result of their prominent ferroelectric properties the photoelectrodes are able to tune the transfer of photo-excited charges generated either in BiFeO₃ or the surface modifiers by manipulating the poling conditions of the ferroelectric domains. At 0 V vs Ag/AgCl the photocurrent could be switched from 0 μA cm^-2 to 10 μA cm^-2 and the open-circuit potential changes from 33 mV to 440 mV when the poling bias of pretreatment is manipulated from -8 V to +8 V. Additionally the pronounced photocurrent from charge injection of the excited surface modifiers could be quenched by switching the poling bias from +8 V to -8 V.