Novel strained layer superlattices for long wavelength IR detectors

In recent years a great deal of interest has been focused in selecting III-V heterostructure materials for infrared detection applications by carefully altering their electrical, optical and transport properties with the help of atomic disorder, biaxial strain, space charge and the materials geometry. Among others, the superlattices (SLs) composed of InAs and GaSb layers with type II band alignments have shown great potential for long wavelength infrared (LWIR) detection applications (Gt 10 mm range). These novel SLs are essentially the III-V equivalent of the HgCdTe materials with comparable absorption coefficients and cut-off wavelengths. The purpose of this work is demonstrate that Ga_xln_1-xSb/lnAs type-II SLs can be tailored with energy gaps for infrared detection applications in the 5-12 mm range.