Electronic structure of (311)-InAs monolayers embedded in GaAs

We have theoretically studied the electronic structure of a (311)-oriented InAs monolayer embedded in GaAs by using the semi-empirical sp(3)s* tight-binding method; (InAs)(1)/(GaAs)(n) [311] superlattices with n = 10 similar to 26 are used for the calculations. The (311)-InAs monolayer induces an electron level (near the conduction-band edge) and a hole level (near the valence-band edge) in the GaAs band gap. The electron-hole energy separation is smaller than the GaAs band-gap energy by 0.06 eV (n = 10) and 0.03 eV (n = 26). The charge densities of the electron state and the hole state are weakly localized near the (311)-InAs monolayer. (C) 1998 Academic Press Limited.