Site of Oxygen Chemisorption on the GaAs(110) Surface

Abstract
We reconcile energy-loss spectroscopy and chemical-shift studies of the oxidation of the GaAs(110) surface, which previously have led to contradictory conclusions about the oxygen bonding site. We have calculated densities of states and 100-eV ultraviolet-photo-electron-spectroscopy (UPS) valence-band spectra to examine the site and molecular species of the chemisorbed oxygen. We conclude that for low coverages oxygen prefers to chemisorb to the surface arsenic atoms and chemisorbs as an O2 molecule.