Density-functional theory calculations were performed, in conjunction with the climbing image nudged elastic band method, in order to study the self-diffusion of O. To this end, a complete set of migration paths for vacancies - as well as interstitials - in wurtzite crystals was derived and expressions were deduced which provided a link to experimentally accessible tracer diffusion coefficients. The calculated migration barriers were consistent with annealing experiments performed on irradiated samples. It was found that vacancy and interstitialcy mechanisms predominated under Zn- and O-rich conditions, respectively. This refuted the suggestion that vacancy mechanisms could operate in O-rich atmospheres. The results provided the basis for a re-interpretation of diffusion experiments, and cleared the way for the development of reliable continuum models for device simulation.

First-Principles Study of Migration Mechanisms and Diffusion of Oxygen in Zinc Oxide. P.Erhart, K.Albe: Physical Review B, 2006, 73[11], 115207 (9pp)