Band Structure of AlAs-GaAs(100) Superlattices

Abstract
We report the results of the first band-structure calculation for AlAs-GaAs superlattice structures consisting of several atomic monolayers of AlAs and GaAs per repeated slab. The tight-binding method is used to investigate the band gaps and the character of the electronic states as a function of the number of monolayers per slab. For any fixed concentration of Al, the material becomes direct as the number of monolayers per slab is increased. The states at the band edges are predominantly in the GaAs layers and die away into the AlAs.