A comprehensive investigation was made of zinc vacancies and interstitial
diffusion in ZnO using ab initio total energy calculations within local density
approximation and the generalized gradient approximation. The zinc interstitial was found to diffuse efficiently, with a barrier of 0.3 to 0.5eV. Diffusion
perpendicular to the c-axis tended to occur via an interstitial mechanism, and
diffusion parallel to the c-axis tended to occur via a kick-out mechanism. The
diffusion of the zinc vacancy was found to be isotropic, and the migration barrier
of the zinc vacancy was about 1.0eV. According to these results, zinc vacancies
were responsible for zinc self-diffusion in n-type ZnO.
First-Principles Study of Diffusion of Zinc Vacancies and Interstitials in ZnO.
G.Y.Huang, C.Y.Wang, J.T.Wang: Solid State Communications, 2009, 149[5-6],
199-204