A comparative study of the structure and stability of O defects in ZnO was presented. By means of first-principles calculations based upon local density functional theory, an investigation was made of the O vacancy and of various interstitial configurations of O in various charge states. The results revealed that dumb-bell like structures were the most thermodynamically stable interstitial configurations for neutral and positive charge states, due to the formation of a strongly covalent O–O bond. For negative charge states, the system preferred a split-interstitial configuration with two O atoms in almost symmetrical positions with respect to the associated perfect lattice site. The calculated defect formation energies implied that interstitial O atoms could provide both donor- and acceptor-like defects.

First-Principles Study of the Structure and Stability of Oxygen Defects in Zinc Oxide. P.Erhart, A.Klein, K.Albe: Physical Review B, 2005, 72[8], 085213 (7pp)