A
superlattice-based
infrared absorber and the matching
electron-blocking and hole-blocking unipolar barriers, absorbers and barriers with graded band gaps, high-performance
infrared detectors, and methods of manufacturing such devices are provided herein. The
infrared absorber material is made from a
superlattice (periodic structure) where each period consists of two or more
layers of InAs, InSb, InSbAs, or InGaAs. The layer widths and
alloy compositions are chosen to yield the desired energy
band gap, absorption strength, and strain balance for the particular application. Furthermore, the periodicity of the
superlattice can be “chirped” (varied) to create a material with a graded or varying energy
band gap. The superlattice based barrier infrared detectors described and demonstrated herein have spectral ranges covering the entire 3-5 micron atmospheric transmission window, excellent
dark current characteristics operating at least 150K, high yield, and have the potential for high-
operability, high-uniformity
focal plane arrays.