Study of interfaces chemistry in type-II GaSb/InAs superlattice structures

There is a considerable interest in type-II GaSb/InAs superlattice system due to several modern applications including infrared detectors. In these studies X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry (SE) have been used for extensive characterization of the surface and interface of GaSb/InAs superlattice. Application of XPS and SE techniques provides precise information from topmost layers of structure and allows excluding presence of GaAs-type interfaces in GaSb/InAs superlattices. It means that Sb-for-As anion exchange does not exist during the molecular beam epitaxial growth of superlattice structures. Simultaneously, these results indicate that InSb-type or GaInSb-type interfaces have been detected in the structures studied.

► The complementary study of InAs/GaSb superlattice interfaces has been proposed.
► InSb and GaInSb interfaces in InAs/GaSb superlattices have been shown.
► The presence of GaAs-type interface in InAs/GaSb superlattices was excluded.
► Sb-for-As exchange during InAs/GaSb superlattice epitaxial growth does not exist.