Atomic and electronic structure of a monolayer ZnSe on the GaAs(110) surface

Abstract

Using the self-consistent pseudopotential method and total energy and force calculations we have studied the equilibrium geometry and the electronic states of a monolayer ZnSe grown on the GaAs(110) surface. On the clean ideal surface the occupied dangling bond band is derived from the p z lobe of As and lies near the bulk valence band maximum, while the unoccupied dangling bond band has s-p z character derived from Ga atoms and lies in the upper half of the fundamental gap. The ZnSe overlayer partially removes the relaxation of the surface atoms, replaces the As and Ga dangling bonds by strong ZnAs and GaSe bonds, but generates Zn and Se dangling bonds with energies close to the bulk band edges.