Atomic and electronic structure of oxygen polyvacancies in ZrO₂

We investigate oxygen-deficient crystalline zirconia using quantum-chemical simulation within the hybrid density functional theory. It was shown that the oxygen vacancy in ZrO₂ is the amphoteric defects and it can act as the electron and hole trap. The most energetically favorable spatial configuration of oxygen polyvacancies in ZrO₂ were calculated. It was found that each subsequent vacancy forms near the already existing one, and no more than 2 removed O atoms, related to Zr atom. The ability of oxygen polyvacancy to act as a conductive filament and to participate in the resistive switching is discussed.