Local atomic structure of semiconductor alloys using pair distribution functions

Abstract

We have developed a method of calculating the pair distribution function of binary semiconductor crystals and pseudobinary alloys with the zinc-blende structures. The pair distribution function is essentially the density-density correlation function and reveals the local structure directly. We have used a simple model using a harmonic potential with bond-stretching and bond-bending forces. The temperature dependence has been incorporated quantum mechanically. Results of this method are presented for both crystals (InAs and GaAs) and alloys (${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{In}}_{\mathrm{x}}$As). These results can be directly compared with x-ray and neutron-diffraction experiments.