BAND DISCONTINUITY IN GAAS/ALAS SUPERLATTICES WITH INAS STRAINED INSERTION-LAYERS

We have theoretically investigated the valence-band discontinuity (Delta(v)) at the (100) GaAs/AlAs interface with the InAs strained insertion-layer. The theoretical calculation is carried out by the self-consistent tight-binding method with the sp(3)s* basis in the (GaAs)(5)/(InAs)(1)/(AlAs)(5)/(InAs)(1) [100] superlattice. Delta E(v) at the GaAs/InAs(1ML)/AlAs interface is calculated to be 0.50 eV, which is practically equal to Delta E(v) = 0.51 eV at the GaAs/AlAs interface with no InAs layers. The insertion of the InAs monolayer changes the detail of valence charge density at the GaAs/AlAs interface but does not change Delta E(v). The result of calculation is in consistent with our experimental measurement by using the x-ray photoelectron spectroscopy.