Geometry and core-level shifts of As on GaAs(110)

The atomic structure of the As-covered GaAs(110) surface in one-monolayer coverage is studied using the pseudopotential density-functional theory. We compare the adsorption geometry of As/GaAs(110) with that of the well-studied isoelectronic Sb/GaAs(110) system and discuss the large difference in the desorption temperature found in both systems, based on the calculated adsorption energies. In addition, we calculate the As 3d and Ga 3d core-level shifts at As/GaAs(110) using: initial-state theory. Our calculations not only produce well the surface components resolved in a recent photoemission experiment, but predict an additional surface core level for the substrate As atom bonded to the adsorbed As atom. [S0163-1829(99)02219-5].