InAs/InAsSb Type-II Strained-Layer Superlattice Infrared Photodetectors
David Z. Ting, Sir B. Rafol, Arezou Khoshakhlagh, Alexander Soibel, Sam A. Keo, Anita M. Fisher, Brian Pepper, Cory J. Hill, Sarath D. Gunapala
Abstract
The InAs/InAsSb (Gallium-free) type-II strained-layer superlattice (T2SLS) has emerged in the last decade as a viable infrared detector material with a continuously adjustable band gap capable of accommodating detector cutoff wavelengths ranging from 4 to 15 µm and beyond. When coupled with the unipolar barrier infrared detector architecture, the InAs/InAsSb T2SLS mid-wavelength infrared (MWIR) focal plane array (FPA) has demonstrated a significantly higher operating temperature than InSb FPA, a major incumbent technology. In this brief review paper, we describe the emergence of the InAs/InAsSb T2SLS infrared photodetector technology, point out its advantages and disadvantages, and survey its recent development.