Resolving the mechanism of oxygen vacancy mediated nonradiative charge recombination in monoclinic bismuth vanadate

We report ab initio time-domain simulations of nonradiative electron-hole recombination in bismuth vanadate (BiVO4). Nonadiabatic molecular dynamics (NA-MD) simulation results demonstrate that the charge recombination in BiVO4 is greatly enhanced by a factor of ~50 after an oxygen vacancy introduced. Oxygen vacancy introduces a sub-gap state close to conduction band (CB) and capable of trapping holes, which in turn rapidly recombine with CB electrons for large transition rate. This is the first report on the excited states dynamics of BiVO4 and provide design principle for achieving high-efficiency light-harvesting devices based on BiVO4 and other transition metal oxides materials.