Reliability of analytical potentials for point-defect simulation in GaAs

Abstract

Molecular dynamics with analytical potentials is commonly used to obtain the distributionof defects produced by energetic particles in elemental and compound semiconductors.Collision cascades simulated by model-potential molecular dynamics are used to collectstatistical data on the defect distribution but the local structure in such materials as GaAsis commonly recognized to be unreliable in comparison to tight-binding or abinitio total energy calculations. These two methods, however, are not practical insimulations of collision cascades because of their large computational workload.In this paper, we analyse the properties of the basic point defects in GaAs asobtained by using different model potentials and compare them to recent ab initiocalculations based on the density-functional theory (DFT) in the local-densityapproximation (LDA). The aim of this work is to evaluate how close the model potentialmolecular dynamics predictions are to the benchmark DFT results and whichmodel potential most accurately predicts realistic local structures of point defects.