Photoelectric properties of BiVO4 thin films deposited on fluorine doped tin oxide substrates by a modified chemical solution deposition process

Abstract

BiVO4 films deposited on Fluorine doped tin oxide glass substrates were successfully prepared by a modified chemical solution deposition process. Structure and optical spectrum analysis show that the resultant BiVO4 films consist entirely of monoclinic scheelite structure and have a narrow band gap of ～2.66 eV. The films were investigated by photoelectrochemical and photovoltaic measurements with regard to hydrogen production and solar energy conversion under visible light. The BiVO4 photoanodes show significantly higher visible light induced photoelectrochemical performance (～1.1 mA/cm2 at 1.0 V vs. Ag/AgCl) than those reported ones, which is very promising for splitting water to H2 and O2. A Schottky BiVO4 solar cell was also investigated for comparison with photoelectrochemical measurements. The correlation between the photoelectrochemical and photovoltaic behavior for BiVO4 was explained. Our research should provide important support for the applications of BiVO4 films or its modified forms such as doping and nanocomposite in heterojunction photoelectrochemical cells and solar cells with suitable energy level alignment at the interface.