We report time-resolved photoluminescence measurements on a set of long-wave infrared InAs / GaSb type II superlattice absorber samples with various widths as a function of temperature and excitation density. Careful analysis of the photoluminescence data determines the minority carrier lifetime and background carrier density as a function of temperature, and provides information on the acceptor energy and density in each sample. Results indicate that carrier lifetime is dominated by Shockley-Read-Hall recombination with a lifetime of ~30 ns at 77 K for all samples. Below 40 K, background carriers are observed to freeze-out in conjunction with increased contributions from radiative recombination. An acceptor energy level of ~20 meV above the valance band is also determined for all samples. Variations of carrier lifetime between each sample do not strongly correlate with absorber width, indicating that barrier recombination is not the dominant factor limiting the carrier lifetime in our samples.
Significantly improved minority carrier lifetime observed in a long-wavelength infrared III-V type-II superlattice comprised of InAs/InAsSb