Bond lengths, force constants and local impurity distortions in semiconductors

Abstract

It is shown that modified overlap interaction, covalent interaction and polar energy introduced by Harrison (1980, 1981) allows the nearest-neighbour spacing in semiconductors to be determined accurately. It is also shown that the force constants of the diamond and zincblende structure semiconductors result from the same covalent and overlap interactions, and are obtained in terms of Herman-Skillman atomic potentials in accordance with experiment. A simple approximation from first principles is proposed for the determination of the local distortion around an impurity atom in a host lattice. The local distortion is calculated for various impurities in GaAs and GaP and is found to be in accordance with the experimentally known systems.