Plane wave density functional theory calculations were made of O vacancies and interstitial O atoms in monoclinic zirconia. After calculating the incorporation energies and structures of interstitial O atoms and formation energies of neutral O vacancies, the electron affinities and ionization potentials of the defects were considered. These properties were especially important at the Si/oxide interface in MOSFET devices, where Si could serve as an electron and hole source. The results demonstrated that interstitial O atoms and positively-charged O vacancies could trap electrons if the electron source (band offset) was more than some 2eV above the top of the valence band.

Modelling of Point Defects in Monoclinic Zirconia. A.S.Foster, V.B.Sulimov, F.L.Gejo, A.L.Shluger, R.M.Nieminen: Journal of Non-Crystalline Solids, 2002, 303[1], 101-7