Bismuth ferrite materials for solar cells: Current status and prospects

Different from classical semiconductor photovoltaic devices, for ferroelectric photovoltaic devices, the open-circuit voltage (Voc) can be four and even more orders of magnitude larger than the band gap of the ferroelectric, and the built-in electric field arising from the remnant polarization of the ferroelectric is throughout the bulk region, which is good for obtaining giant power conversion efficiency. Among ferroelectric materials, BiFeO3 with remnant polarization of as high as ∼100 μC/cm2 has the narrowest direct band gap (∼2.7 eV). These indicate that high power conversion efficiency may be obtained in BiFeO3-based photovoltaic devices. Also, some significant research results about photovoltaic effects of BiFeO3 materials have been recently acquired. In order to better promote the development of BiFeO3-based photovoltaic devices, in this paper, we present a comprehensive review on the latest research progress in photovoltaic effects of BiFeO3 materials with different kinds of topography, including bulk, thin film, and nanomaterials.