Comment on ‘‘Temperature limits on infrared detectivities of InAs/In_xGa_1−xSb superlattices and bulk Hg_xCd_1−xTe’’ [J. Appl. Phys. 74, 4774 (1993)] Available to Purchase

Theoretical calculations [P. M. Young, C. H. Grein, H. Ehrenreich, and R. H. Miles, J. Appl. Phys. 74, 4774 (1993)] comparing optimized InAs/In_xGa_1−xSb superlattice (SL) to bulk Hg_xCd_1−xTe (MCT) detectors claim that the SL detector is superior to MCT for 11 μm operation. The referenced analysis is incomplete for three reasons: first, radiative recombination is ignored, resulting in unrealistically high SL performance predictions; second, the Auger‐7 (chlh) mechanism is assumed to limit lifetime in p‐type MCT, while longer radiatively limited lifetime has been observed experimentally; and finally, optimized MCT devices are routinely fabricated in thin epitaxial layers, which give higher performance than is obtained in bulk material. A more complete theory for SL detectors is unlikely to predict higher performance than that of MCT detectors, since MCT detectors are theoretically limited by radiative processes. Measured MCT detector performance in near agreement with the radiative limit has been observed.