Photovoltaic Effect in BiFeO₃ Film Deposited by RF Magnetron Sputtering.

A polycrystalline BiFeO₃ film was deposited on ITO substrate by RF magnetron sputtering method. Small crystallite size and compact structure are obtained for BiFeO₃ film which has the excellent ferroelectric properties. The measured photovoltaic response reveals an open-circuit voltage of ~0.52 V and a short-circuit current density of ~10 A/cm² under the illumination of 100 mW/cm² irradiance. Moreover, a tunable photovoltaic effect with light illumination is observed under different voltage sweep mode. High initial sweep voltage can enhance the photovoltaic effect largely, however, the photovoltaic response decreases with the increase of voltage sweep interval. The results indicate the ferroelectric polarization plays an important role in the photovoltaic effect.