Ferroelectric photovoltaic response near to visible light region in BiFeO3/BiVO4 composite films

BiFeO3/BiVO4 composite films have been prepared via the solution-gelation technique. The phase structure, dielectric constant, ferroelectricity, optical band-gap, photovoltaic spectral response and J-V performance were investigated. It is found that the composite films exhibit a typical ferroelectric behaviors and the improved leakage and dielectric properties. Obvious ferroelectric photovoltaic effect is obtained with high short circuit current density and open circuit voltage for BiFeO3/BiVO4 composite films under the white-light illumination. And the photovoltaic spectral responses of the normalized current are near to the visible light region, which originates from the narrow band-gap of BiFeO3/BiVO4 composite films. This work provides an available way of controlling ferroelectric photovoltaic response of ferroelectric films and promising applications in lighting emitting diode and other photo-electron related devices.