Interaction of oxygen vacancy and its impact on transmission coefficient in oxygen-deficient titanium dioxide: Ab initio calculations

Ab initio calculations on the interaction of the oxygen vacancy and its impact on the transmission coefficients in oxygen‐deficient TiO2 are reported. It is found that the separated oxygen vacancies or divacancies produce partial shallow defect energy levels below the conduction‐band edge as weak interactions between these vacancies. On the contrary, for the ordering oxygen divacancies, we observe that the defect energy levels fill in the bandgap. A much higher extent is found for the ordering oxygen divacancies in both columns of the supercell due to the appearance of many reduced Ti3+ ions. As a result, these oxygen divacancies expand the transmission range and improve the transmission coefficients. The microscopic origin of the oxygen‐vacancy interaction is helpful to clarify the mechanism of the resistive switching phenomenon.