Segregation effects on the optical properties of (InAs)/(GaSb) superlattices

We combine a kinetic model of MBE growth with the empirical pseudopotential band structure method to study the effects of interfacial disorder and segregation on the optical properties of InAs/GaSb superlattices. We fit the layer-by-layer growth model to the observed STM segregated profiles, extracting surface-to-subsurface atomic exchange energies. These are then used to obtain a detailed simulated model of segregated InAs/GaSb superlattices with atomic resolution. The application of the pseudopotential calculations to such structures reveals remarkable electronic consequences of segregation, including a blue shift of band gap with increasing sample growth temperature.