Impact Ionization and Auger Recombination in Semiconductors: Implementation Within the Flapw Code

We present a method to calculate impact ionization and Auger recombination rates within density functional theory and a screened-exchange approach and implement it in the all- electron FLAPW method. We investigate the dependence of the overlap matrix elements as a function of the states involved along the main symmetry lines of the Brillouin zone. Our results for the final impact ionization rates along the main symmetry lines of the Brillouin zone. Our results for the final impact ionization rates along τ — X and τ —L directions for GaAs show a strong anisotropy imposed by energy and momentum conservation and related to the use of a realistic and accurate sX-LDA band structure.