Abstract High-quality polycrystalline BiFeO 3 (BFO) films have been of great interest for many electrical and optical applications, however the fabrication of polycrystalline BFO films offering a large remnant polarization and low leakage current are difficult. In this work, polycrystalline BFO films were deposited using a radio frequency magnetron sputtering method. It was found that the remnant polarization of BFO deposited on ITO is about three and seventy times larger than films deposited on Pt and FTO, respectively. Film quality was highly dependent on the film thickness, with a thinner film displaying greater leakage. Despite the degradation in ferroelectric performance, however, the photovoltaic response was enhanced. Ultrathin BFO films therefore broaden the potential applications for ferroelectric photovoltaic devices by improving their carrier mobility, and allow for fine-tuning of their band structure when combined with semiconductors and electrodes.