Polarization-controlled leakage current and photovoltaic effect in highly preferentially oriented BiFeO3 film

Highly preferentially oriented polycrystalline BiFeO₃ thin film was grown on FTO/glass substrate by a sol–gel method annealed at 500 °C. XRD result showed that the film adopts highly (100) preferential orientation. SEM results indicate that the film is composed of large grains of 40–200 nm and the thickness is about 320 nm. Room temperature saturated polarization and large Pr ~55 μC/cm² were obtained. Leakage current was substantially reduced by the controlling of ferroelectric polarization. Polarization-modulated conduction mechanism was studied. Moreover, substantial photovoltaic effect was observed.