Intrinsic open-circuit voltage and short-circuit current of ferroelectric photovoltaic effect

Photovoltaic effect of BiFeO3 (BFO) films prepared by sol–gel method was investigated. Both J–V curves with different polarization under illuminated conditions and the J–V curves with different polarization under dark conditions are measured. On this basis, this work provides a law that characterizes the intrinsic open-circuit voltage and short-circuit current density of BiFeO3 films by the differentials between illuminated and dark open-circuit voltage, as well as short-circuit current density. Furthermore, the components of open-circuit voltage are determined in detail. The practical conclusions show that it is accurate to use intrinsic open-circuit voltage and short-circuit current to reflect the strength of ferroelectric photovoltaic effect, not the values under illumination.