Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 26: II-VI semiconductors II

HL 26.9: Vortrag

Dienstag, 28. März 2006, 17:15–17:30, POT 51

First-principles study of migration mechanisms and diffusion of oxygen in zinc oxide — •Paul Erhart and Karsten Albe — Technische Universität Darmstadt, Institut für Materialwissenschaft, Petersenstr. 23, 64287 Darmstadt

We have performed density-functional theory (DFT) calculations in conjunction with the climbing image-nudged elastic band method (CI-NEB) in order to study the self-diffusion of oxgyen in zinc oxide. To this end, we have generalized the migration paths accessible for vacancies as well as interstitials in wurtzite crystals and derived expressions which provide the link to experimentally accessible tracer diffusion coefficients. The calculated migration barriers are consistent with annealing experiments on irradiated samples. We find that vacancy and interstitialcy mechanisms dominate under zinc and oxygen-rich conditions, respectively. Either mechanism can in principle lead to the experimentally observed diffusivities. However, diffusion experiments are normally carried out in oxygen atomosphere and will, therefore, sample oxygen interstitial diffusion. Our results provide the basis for the (re-)interpretation of previous and future diffusion experiments, and pave the way towards the development of reliable continuum models for device simulation.