A comprehensive investigation of oxygen vacancy and interstitial diffusion in ZnO was performed using ab initio total energy calculations with both the local density approximation and the generalized gradient approximation. Based upon the calculation results, oxygen octahedral interstitials were fast diffusers, contributing to annealing processes, as well as being responsible for the self-diffusion of oxygen for n-type ZnO, and oxygen vacancies were responsible for the self-diffusion of oxygen for p-type ZnO.

First-Principles Study of Diffusion of Oxygen Vacancies and Interstitials in ZnO. Huang, G.Y., Wang, C.Y., Wang, J.T.: Journal of Physics - Condensed Matter, 2009, 21[19], 195403