The emergence of InAs/InAsSb type-II strained layer superlattice barrier infrared detectors

The InAs/InAsSb (Gallium-free) type-II strained-layer superlattice (T2SLS) is an adjustable band gap, broad-band III-V infrared detector material that has emerged in recent years as an alternative to the more established InAs/GaSb type-II superlattice. We have reported results on a mid-wavelength focal plane array (FPA) based on the InAs/InAsSb T2SLS unipolar barrier infrared detector architecture. Significantly, the FPA exhibits very good operating characteristics at 160 K, demonstrating a considerably operating temperature advantage over the MWIR market-leading InSb FPAs, while maintaining III-V semiconductor manufacturing robustness. In this article we summarize the development at the NASA Jet Propulsion Laboratory leading to the mid-wavelength InAs/InAsSb T2SLS infrared detectors, provide a brief look at the history of the development of the InAs/InAsSb T2SLS absorber, and survey the current status of InAs/InAsSb T2SLS detectors.