First-principles calculation of the temperature dependence of the optical response of bulk GaAs

TL;DR

This paper introduces a new computational method to predict how the optical properties of bulk GaAs change with temperature by averaging over thermally perturbed configurations derived from molecular dynamics simulations.

Contribution

It presents a novel approach that explicitly incorporates lattice vibrations to accurately model the temperature-dependent optical response of GaAs.

Findings

The method accurately predicts energy shifts in dielectric function with temperature.

The approach captures broadening effects due to thermal vibrations.

Results agree well with experimental observations.

Abstract

A novel approach has been developed to calculate the temperature dependence of the optical response of a semiconductor. The dielectric function is averaged over several thermally perturbed configurations that are extracted from molecular dynamic simulations. The calculated temperature dependence of the imaginary part of the dielectric function of GaAs is presented in the range from 0 to 700 K. This approach that explicitly takes into account lattice vibrations describes well the observed thermally-induced energy shifts and broadening of the dielectric function.