First-principles studies of the effect of oxygen vacancies on the electronic structure and linear optical response of multiferroic BiFeO3

Oxygen vacancies (OVs) have a significant influence on the carrier mobility and optical conductivity in transition metal oxides. In this letter, using density-functional theory, we investigate the effect of OVs on the optical response in multiferroic BiFeO3. Within the generalized gradient approximation plus the on-site Coulomb repulsion, we show that the absorption edge shifts to lower energy with the increase of OV concentration, while the...