An atomistic model for the simulation of acoustic phonons, strain distribution, and Gruneisen coefficients in zinc-blende semiconductors
Date of this Version5-6-2004
This document has been peer-reviewed.
An accurate modeling of phonons, strain distributions, and Gr¨uneisen coefficients is essential for the qualitative and quantitative design of modern nanoelectronic and nanooptoelectronic devices. The challenge is the development of a model that fits within an atomistic representation of the overall crystal yet remains computationally tractable. A simple model for introducing the anharmonicity of the interatomic potential into the Keating two-parameter valence-force-field model is developed. The new method is used for the calculation of acoustic phonon and strain effects in zinc-blende semiconductors. The model is fitted to the Gr¨uneisen coefficients for long-wavelength acoustic phonons and reproduces the response to strain throughout the Brillouin zone in reasonable agreement with experiment.