Carrier recombination in mid-wave infrared InAs/InAsSb superlattices

Measurements of carrier recombination rates using a temperature-dependent time-resolved differential transmission technique are reported for mid-wave infrared $InAs/InAs_{1-x}Sb_{x}$ type-2 superlattices (T2SLs). By engineering the layer widths and antimony compositions a 16K band-gap of $\sim$ 238 meV was achieved for all five unintentionally doped T2SLs. Carrier recombination rates were determined for all five samples by fitting a rate equation model to the density and temperature dependent data. Minority-carrier lifetimes as long as 22$\mu s$ were measured at 14K, while lifetimes in excess of 2$\mu s$ were measured for all five samples at 200K. The minority-carrier lifetimes were observed to generally increase with increasing antimony content. While minority-carrier lifetimes are much longer than those observed in InAs/Ga(In)Sb T2SLs, Auger recombination processes were found to be more prominent in the Ga-free T2SLs. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000. This research was funded by the U.S. Government.