Chemisorption of Cl on GaAs: a density functional-LCAO approach

A linear combination of atomic orbitals method supplemented by a local density approximation is applied to the calculation of Cl adsorbed on GaAs(110). We present results for coverages of 1/2 and 1 monolayer. Our results show that Cl in the early stages of deposition tends to adsorb on Ga, although the deposition of Cl-pairs on Ga and As nearest neighbours is very likely. We also find that the majority deposition of Cl on Ga tends to pin the interface Fermi level in the As-like dangling bond, near the valence band top, These results are in good agreement with the available experimental data.