Phys. Rev. B 57, 4486 (1998).

An ab initio study of atomic geometry, electronic states and bonding for H2S-adsorption on III-V(110)-(1x1) surfaces


M. Çakmak and G.P. Srivastava

Department of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK


Abstract

Ab initio calculations, based on pseudopotentials and the density functional theory, have been made to investigate the equilibrium atomic geometry, electronic states and bonding of the H2S molecule on the InP(110), GaAs(110) and GaP(110) surfaces within a dissociative adsorption model. In general the adsorption of H2S on the three semiconductors shows similar behaviour. The calculated average distances between the topmost InP, GaAs and GaP layer and the sulphur atom are 1.87, 1.67, and 1.65 A, respectively. In all the cases studied here, the fundamental band gap is free of surface states, with an occupied surface state close to the valence band maximum. The calculated electronic states are in agreement with reported angle-resolved photoemission data.