Electronic and structural properties of the oxygen vacancy in BaTiO3

The electronic and structural properties of the oxygen vacancy (VO) in cubic BaTiO3 are studied using first-principles calculations based on a hybrid Hartree-Fock density functional approach. Our calculations identify the double shallow donor behavior of V-O, indicating its contribution to the n-type conductivity. In addition, a metastable configuration is found, which shows an off-symmetric atomic structure around V-O in conjunction with deep localized electronic states in the band gap. Based on the identified characteristics of V-O, the previous experimental and theoretical findings are explained. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3583460]