Diffusion of zinc vacancies and interstitials in zinc oxide

The self-diffusion coefficient of zinc in ZnO is derived as a function of the chemical potential and Fermi level from first-principles calculations. Density functional calculations in combination with the climbing image-nudged elastic band method are used in order to determine migration barriers for vacancy, interstitial, and interstitialcy jumps. Zinc interstitials preferentially diffuse to second nearest neighbor positions. They become mobile at temperatures as low as 90-130 K and therefore allow for rapid defect annealing. Under predominantly oxygen-rich and n-type conditions self-diffusion occurs via a vacancy mechanism. (c) 2006 American Institute of Physics.