Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 32: Poster I: Group II - Oxides

HL 32.2: Poster

Dienstag, 23. März 2010, 18:30–20:30, Poster D1

Oxygen vacancy and nitrogen substitutional in ZnO: An ab initio study — •Fabian Hachenberg, André Schleife, Jürgen Furthmüller, and Friedhelm Bechstedt — Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany

In the last decade, the wide-gap semiconductor ZnO has attracted large attention due to its potential use in optoelectronic applications. Still the difficulty of reliable and reproducible p-type doping is an obstacle in using ZnO for light-emitting devices. Therefore, a comprehensive understanding of the behaviour of point defects in ZnO is crucial. We present first-principles calculations for the electronic and structural properties of two important point defects in different charge states in ZnO. Using a supercell approach we study the oxygen vacancy and the nitrogen substitutional. The calculations are carried out using generalized-gradient corrected density functional theory (DFT-GGA) and pseudopotentials within the projector-augmented wave (PAW) framework. For studying the electronic structure we also employ the GGA+U method and the nonlocal HSE03 exchange and correlation functional. We discuss errors induced by the semilocal GGA, as well as supercell-specific finite-size effects. We derive formation energies and transition levels for both point defects and compare to other calculations and also experimental results.