Based on ab initio total energy calculations, Li, Na and Ag interstitials were found

to be stable with at least a 1.56eV energy barrier to transform to a zinc

substitutional site in ZnO, whereas interstitial K had a relatively small energy

barrier of 0.79eV. The isolated dopant substitutional defects (LiZn, NaZn, KZn and

AgZn) were found to be rather stable, with at least a 3.4eV energy barrier to

transform to an interstitial site. All of the dopant interstitials (Lii, Nai, Ki and Agi)

were fast diffusers. The diffusion of Li interstitial was isotropic, whereas the

diffusion of Na, K and Ag interstitials was highly anisotropic. Fundamental

processes of the vacancy-assisted mechanisms were systematically investigated and

specific values of the energy barriers were obtained.

First-Principles Study of Diffusion of Li, Na, K and Ag in ZnO. G.Y.Huang,

C.Y.Wang, J.T.Wang: Journal of Physics - Condensed Matter, 2009, 21[34],

345802