Ab initio study of gallium arsenide surface passivation by sulfur

Abstract

The GaAs(100) surface is modeled by using atomic clusters in order to study the effects of passivation with sulfur. Both the Ga- and the As-terminated surfaces are tied off with S atoms in a 2 {times} 1 reconstruction. The most stable structure is established on the basis of ab initio Hartree-Fock calculations. It is found that after quenching the dangling orbitals with hydrogen and passivating the surface with S the density of surface states in the band gap region is appreciably reduced.