An Overview of the Electronic Properties of InAs<sub>1-x</sub>Sb<sub>x</sub> Strained-Layer Superlattices (0 ≤ x ≤ 1)

There have been few attempts to "bandgap engineer'' In(AsSb) semiconductors although In(AsSb) alloys have the smallest bandgaps and effective masses among the III-V semiconductors. In(AsSb) may prove useful for high speed devices, and this system is an obvious starting point to extend the optical response of III-V semiconductors to longer wavelength for infrared detectors and lasers. In this paper we summarize studies of the electronic and optical properties of In(AsSb) strained-layer superlattices (SLSs) for a wide range of compositions. Previously, long wavelength infrared response was observed at low As content in these SLSs, and we concluded that a type II (or staggered) band offset occurs in the In(AsSb) system. Prototype infrared detectors have been fabricated from these structures.