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HL: Halbleiterphysik

HL 16: Poster Ia

HL 16.18: Poster

Friday, March 4, 2005, 16:30–19:00, Poster TU E

Ab initio impact ionization rate in GaAs, GaN, and ZnS — •Angelika Kuligk, Niels Fitzer, and Ronald Redmer — Universität Rostock, Institut für Physik, 18051 Rostock

We have performed ab initio band structure calculations for GaAs, GaN, and ZnS within density functional theory (DFT) using an exact exchange formalism with a local density approximation (EXX-LDA) for correlations. The wave-vector dependent microscopic impact ionization rate (IIR) is determined for these materials. A strong asymmetry of the IIR as well as a pronounced influence of the band structure is found. We compare these results with scattering rates obtained from band structures calculated with the empirical pseudopotential method (EPM). We present also energy-averaged impact ionization rates which can be applied in Monte Carlo simulations of high field electron transport.