High photoconductive gain in lateral InAsSb strained-layer superlattice infrared detectors

Both large photoconductive gain and long wavelength photoresponse were observed in lateral photodetectors constructed from type II, InAsSb, strained-layer superlattices. In a novel, four-layer superlattice, gain values as large as 90 are reported with a long wavelength cutoff of 8.7 μm at 77 K. The gain is sensitive to the structure and composition of the superlattice, and the sweepout of minority carriers is eliminated with the appropriate contacts.