Electronic structure of the Al-GaAs(110) surface chemisorption system

Abstract

The electronic structure of an ordered half-monolayer coverage of Al on the GaAs(110) surface is examined using a self-consistent pseudopotential approach. We find the surface geometry in which the Al adatom is chemisorbed to a substrate Ga atom is the one most compatible with experimental and theoretical considerations. Our conclusion on the chemisorption site is in agreement with recent theoretical calculations employing quantum-chemical cluster methods, but is in contrast with previous band calculations which have suggested an anion chemisorption site. In addition, we assert the surface dipole of Al chemisorbed on intrinsic GaAs is positive; some previous interpretations have suggested that this dipole is negative.