Theoretical Study of the Adsorption of Halogens on GaAs Surfaces

The structure and properties of absorbed fluorine and chlorine atoms on GaAs surfaces are investigated. The energies of surface species' localized vibrations are determined. Our results show that localized As–Cl and Ga–Cl valence vibrations occur in the 40 and 50 meV regimes, respectively, while As–F and Ga–F vibrations are found in the 90 and 80 meV regimes, respectively. Comparisons are made with experimental high resolution electron energy loss spectroscopy spectra. Our results accord well with a variety of experimental data.