First-principles study of diffusion behaviour of point defects in the O-terminated (0001) surface in wurtzite ZnO

A detailed first-principles study of the diffusion behaviour of point defects in the O-terminated (0001) surface in wurtzite ZnO was performed. The O vacancy and interstitial are found to diffuse much more easily in surface than in bulk. The Zn vacancy has a similar migration barrier for both bulk and surface, but has much smaller barrier for the diffuse-in process. The Zn interstitial is difficult to diffuse in the surface directly, but it can diffuse into the bulk relatively easily. Specific values of corresponding migration barriers are obtained.