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

Minority carrier lifetime, τ, in type-2 strained-layer superlattices (SLSs) and in long-wave Hg0.78Cd0.22Te (MCT) was measured by optical modulation response technique. It was shown that at 77 K radiative recombination can contribute to the measured τ values. The Shockley–Read–Hall (SRH) lifetimes were attained as 100 ns, 31 ns, and more than 1 μs 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.