Short-period InAsSb-based strained layer superlattices for high quantum efficiency long-wave infrared detectors

Infrared detector barrier heterostructures with strained layer superlattice (SLS) absorbers different periods were compared. The first was a reference using conventional heterostructure low temperature energy gap corresponding to wavelength of 10 ?m in 2- ?m-thick undoped absorber 10.9 nm period InAs/InAsSb 0.36 compositions grown directly on GaSb substrate. second structure, contrast, used significantly shorter 4.3 InAsSb 0.3 /InAsSb 0.55 compositions, similar gap, and thickness, which 6.2 Å lattice constant GaIn Sb virtual substrate GaSb. It found that the short SLS, vertical hole mobility minority carrier lifetime range 80–150 K factor 2–3 greater than structure. improvement attributed effect delocalization. latter results an increase optical absorption coefficient quantum efficiency.