A comprehensive investigation was made of the zinc vacancy and interstitial

diffusion in ZnO by using ab initio total energy calculations within the local

density approximation and the generalized gradient approximation. The Zn

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 to

the zinc vacancy was about 1.0eV. Based upon these results, it was concluded that

zinc vacancies were responsible for the self-diffusion of zinc for 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