Minority carrier lifetime in type-2 InAs-GaSb strained-layer superlattices and bulk HgCdTe materials

Minority carrier lifetime, tau, in type-2 strained-layer superlattices (SLSs) and in long-wave Hg(0.78)Cd(0.22)Te (MCT) was measured by optical modulation response technique. It was shown that at 77 K radiative recombination can contribute to the measured tau values. The Shockley-Read-Hall (SRH) lifetimes were attained as 100 ns, 31 ns, and more than 1 mu s for midwave infrared superlattices, long-wave infrared (LWIR) superlattices, and MCT correspondingly. The nature of the difference between the SRH lifetimes in LWIR superlattice and MCT is discussed. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3476352]