The structural and optical properties of Ag/Cu co-doped BiVO4 material: A density functional study

Abstract

Density Functional Theory (DFT) calculation was used to conduct a systematic theoretical study on the structural, electrical, and optical properties of pure, Ag-doped, Cu-doped, and (Ag, Cu) co-doped BiVO4. The simulated electronic structure showed that the synergistic effect of Ag/Cu co-doping can induce new energy states due to hybridization in the forbidden gap that resulted in decrease in the band gap of BiVO4, which indicates a decline in photogenerated electron-hole pair recombination and an understandable shift of absorption edge towards higher wavelength region. The (Ag, Cu) co-doped BiVO4 has a higher optical absorption intensity than pure Ag or Cu doped BiVO4, demonstrating the synergistic effect of Ag 4d and Cu 3d states. Furthermore, DFT calculations have been analyzed to explore the collective effect of Ag or/and Cu doping and the intrinsic oxygen vacancy defects in BiVO4.