Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 51: Poster IV

HL 51.64: Poster

Donnerstag, 28. Februar 2008, 16:30–19:00, Poster D

Structure, phase stability, and gaps of wurtzite MgZnO and CdZnO alloys — •Matthias Eisenacher¹, André Schleife¹, Lara Kühl Teles², Jürgen Furthmüller¹, and Friedhelm Bechstedt¹ — ¹Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität and European Theoretical Spectroscopy Facility (ETSF), Max-Wien-Platz 1, 07743 Jena, Germany — ²Departamento de Física, Instituto Tecnológico de Aeronáutica, Comando-Geral de Tecnologia Aeroespacial, 12228-900 São José dos Campos, SP, Brazil

Recently II-VI compounds became more and more important as materials with potential applications in optoelectronic devices. For pseudomorphic heterostructures it is highly desirable to adjust the material properties carefully. Alloys allow to tailor a certain material property. Also from a theoretical point of view the investigation of mixed crystals is a challenge.

We apply density functional theory and the generalized quasichemical approximation together with a cluster approximation to study MgZnO and CdZnO alloys in the wurtzite structure. The combination of these ab initio approaches enables us to study the thermodynamics of these systems as well as the structural and electronic properties with varying composition. We construct phase diagrams versus composition and temperature and calculate bond lengths as well as gap-bowing parameters for the two alloys versus average composition.