Charge Localization in Defective BiVO₄

Abstract

We study the native\ndefects in bismuth vanadate using hybrid density\nfunctional theory. We pay special attention to where excess charges\nlocalize by considering different polaronic distortions and find that\ncharge localization has a profound effect on the local chemical environment\naround certain defects. In particular, oxygen dimerization may occur\nin the presence of acceptor defects. On the basis of Fermi level pinning\ndue to compensation between donors and acceptors we additionally find\nthat intrinsic p-type conductivity is difficult to achieve in BiVO₄, in good agreement with experimental observations. Our results\ngive new insights into the defect chemistry of bismuth vanadate and\nact as a guide for future studies on defects in complex metal oxides.