Alloying effect in the electronic properties of thin GaAs/AlAs superlattices

A local pseudopotential method within the Xalpha scheme is used to investigate the electronic structure of (GaAs)5(AlAs)5, (GsAs)5(Ga0.8Al0.2As)5 and (Ga0.8Al0.2As)5(AlAs)5 superlattices along the (110) growth direction. It is shown that the alloying of the GaAs or AlAs layers produces significant changes in the dispersion and confinement of the electronic states in the superlattice (GaAs)5(AlAs)5. In particular, the authors find that the effect of alloying the GaAs layers is to change the behaviour of Gamma of the superlattice from type I to type II.