sp3s∗ tight-binding calculation of band edges and effective masses of InAs/GaSb superlattices with different interface structures

The band edge energy and effective mass of InAs/GaSb type II superlattices on a (001) GaSb substrate have been investigated using the empirical sp3s∗ tight-binding method. The influence of interfacial bonds on electronic properties has been clarified in typical superlattices of (InAs)n(GaSb)n with C2v point group symmetry and both (InAs)n(InSb)(GaSb)n and (InAs)n(GaSb)n(GaAs) superlattices with D2d point group symmetry. In the short period region of superlattices, we found that the band offsets in the vicinity of the hetero interfaces significantly impact on the band edges and that interfacial Ga-As bonds specifically cause large anisotropy of in-plane effective masses in (InAs)n(GaSb)n superlattices.