Abstract
We present the results of a fully first-principles calculation of impact ionization rates in GaAs within the density functional theory formalism, using a screened-exchange approach and the highly accurate all-electron full-potential linearized augmented plane wave (FLAPW) method. The calculated impact ionization rates show a marked orientation dependence in k space, indicating the strong restrictions imposed by the conservation of energy and momentum. This anisotropy diminishes as the impacting electron energy increases. A Keldysh type fit performed on the energy-dependent rate shows a rather soft edge and a threshold energy greater than the direct band gap. The consistency with available Monte Carlo and empirical pseudopotential calculations shows the reliability of our approach and paves the way to ab-initio calculations of pair production rates in new and more complex materials.
Original language | English |
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Pages (from-to) | 421-424 |
Number of pages | 4 |
Journal | Journal of Computational Electronics |
Volume | 1 |
Issue number | 3 |
DOIs | |
Publication status | Published - Oct 1 2002 |
Keywords
- density functional theory
- GaAs
- impact ionization
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Modelling and Simulation
- Electrical and Electronic Engineering