ABSTRACT
The roughness and intermixing at the heterointerfaces in InAs/GaSb superlattice's have been studied by both high-resolution transmission electron microscopy. There is interest in InAs/AlSb/GaSb heterostructures for fundamental studies and device applications. Solid-source molecular-beam epitaxy (MBE) is a widely used technique for the growth of InAs/AISb/GaSb heterostructures. An important issue for the growth of group III arsenide-antimonide heterostructures is the unintentional incorporation of As into the antimony-containing layers from the As background in the MBE growth chamber. The heteroepitaxial growth of InAs/AlSb/GaSb heterostructures on GaAs substrates opens a new, quite uncommon possibility for the structural characterization, applying far-infrared spectroscopy. Regarding energies of optical interband transitions, interface states in the forbidden gap may also play a role acting as initial or final states of such transitions. Photoluminescence provides information on the energy of the effective band gap in type II heterostructures provided that indeed band-to-band transitions are observed.
