A dye-free photoelectrochemical (PEC) solar cell based on BiVO 4 oxide film was developed. Without a bias, a high incident photo-to-current conversion efficiency (IPCE) of 43% was obtained and the solar energy conversion efficiency of the cell was 14 times higher than the record efficiency of Fe 2 O 3 PEC solar cells. Ultra-fast transient absorption spectroscopy was utilized to investigate the mechanism of the different photoelectric performances. The results revealed that there was a longer lifetime of photogenerated carriers in BiVO 4 than that in Fe 2 O 3 . It was helpful to develop other suitable photoelectrode materials for dye-free PEC solar cells.