Published online by Cambridge University Press: 31 January 2011
We performed first-principle simulation for the study of oxygen vacancy defect in rutile TiO2 based on density functional theory. The effects of a vacancy on the electronic structure of rutile TiO2 were studied. Here we have employed neutral and charged oxygen vacancy in the supercell to address the resistance switching mechanism. Neutral vacancy induces the band gap states at deep level, ∼0.7 eV below the conduction band minimum, which is occupied by highly localized electrons. The calculation results of positively charged oxygen vacancy show that larger atomic relaxation surrounding oxygen vacancy results in the stretching of Ti-O bond around vacancy, thus band gap states are formed near the conduction band minimum.