Ab initio modeling of diffusion in indium oxide

Migration barriers of intrinsic defects in cubic indium oxide are calculated by means of first-principles calculations within density-functional theory using the nudged-elastic-band method. Within the open C-type (bixbyite) structure of In2O3 there is a large variety of distinct migration paths involving the fourth-neighbor shell. Effective migration energies and diffusion length are calculated by means of kinetic Monte Carlo simulations. We show that cation barriers have generally higher migration energies as compared to oxygen defects, which diffuse via correlated jumps. Moreover, there are distinct diffusion paths for anion and cation interstitials while structural vacancies within the bixbyite structure do not give rise to an enhanced diffusion.