Charge Localization in Defective BiVO₄

Abstract

We study the native defects in bismuth vanadate using hybrid density functional theory. We pay special attention to where excess charges localize by considering different polaronic distortions and find that charge localization has a profound effect on the local chemical environment around certain defects. In particular, oxygen dimerization may occur in the presence of acceptor defects. On the basis of Fermi level pinning due to compensation between donors and acceptors we additionally find that intrinsic p-type conductivity is difficult to achieve in BiVO 4 , in good agreement with experimental observations. Our results give new insights into the defect chemistry of bismuth vanadate and act as a guide for future studies on defects in complex metal oxides.

Accelerating water oxidation on BiVO4 photoanodes via surface modification with Co dopants

“…The resulting relative formation energies are shown in Fig. 3a for chemical potentials corresponding to O-poor and Bi-rich conditions that are expected for n-type BiVO 4 according to a previous theoretical study by Österbacka et al 49 Formation energies for other chemical potentials are shown in Fig. S6.…”

Enhancing the photoelectrochemical activity of monoclinic BiVO4by discretizing oxygen vacancies: insights from DFT calculations

“…This demonstrates that the oxygen vacancy systems are unstable compared to the pristine BiVO 4 system. 43 This can well explain the phenomenon of structure collapse caused by the oxygen vacancies in the experiment.…”

New Views on Carrier Diffusion and Recombination by Combining Small Perturbation Techniques: Application to BiVO4 Photoelectrodes

“…A possible origin of the differences between obtained in each case may be related to the presence of structural defects, mainly oxygen vacancies, on the surface of BiVO 4 , as it has been extensively reported. [ 61–63 ] These defects can act as recombination centers, known as surface traps, that could ultimately decrease the . [ 64–66 ] Indeed, surface recombination was reported as the main limiting process on the performance of BiVO 4 photoanodes.…”