Many types of optoelectronic devices can be enhanced signicantly through the introduction of quantum connement in reduced-dimensionality heterostructures. This was the main motivation for the study of superlattices (SLs) as an alternative infrared detector materials. The HgTe/CdTe SL system was proposed in 1979, only a few years after the rst GaAs/AlGaAs quantum heterostructures were fabricated by MBE. It was anticipated that superlattice infrared materials would have several advantages over bulk HgCdTe (the current industry standard) for this application:

a higher degree of uniformity, which is importance for detector arrays; ◾

smaller leakage current due to the suppression of tunneling (larger effective masses) available ◾ in superlattices; and

lower Auger recombination rates due to substantial splitting of the light-and heavy-hole bands ◾ and increased electron effective masses.