ORDERING OF CONDUCTION-BAND STATES IN (GAAS)N (ALAS)N [001] AND [110] SUPERLATTICES

The local empirical pseudopotential theory, implemented via the S-matrix layer method has been used to study the conduction band state ordering in (GaAs)n(AlAs)n superlattices grown in the [001] and [110] directions. An oscillatory dependence of the energies on the layer thickness n is found. It is shown that the GAMMA-state becomes the lowest energy state for n greater-than-or-equal-to 8 in the [001] case, and for n greater-than-or-equal-to 12 in the [110] case.