Chemisorption of oxygen and aluminum on the GaAs (110) surface from a b i n i t i o theory

Abstract
We have applied quantum chemical methods to the structure of the clean GaAs (110) surface and the chemisorption of oxygen and aluminum. We find that results for small clusters give geometries for the clean surface in agreement with those observed experimentally. We propose that an intermediate stage of oxidation would exist in which the O atom binds to a surface As. Our studies indicate that the initial site for Al chemisorbed on GaAs (110) has the Al bonded to the surface Ga. Geometries and chemical shifts are reported for both O and Al on GaAs (110). The chemical shifts are in agreement with recent experimental results.