Photoluminescence study of carrier recombination processes in InAs/InAsSb type-II superlattices

Abstract

This paper reports a study of Shockley-Read-Hall, radiative, and Auger recombination processes in a series of molecular beam epitaxy grown InAs/InAsSb mid-wavelength infrared and long-wavelength infrared type-II superlattice samples using temperature-and excitation -density-dependent photoluminescence measurements, which are carried out from 12 to 77 K with excitation densities from 5 mW/cm 2 to 20 W/cm 2 . A theoretical model is applied to describe the relation between integrated photoluminescence intensity and excitation density. Shockley-Read-Hall, radiative, and Auger recombination coefficients are extracted by fitting this relation. The results show that the Shockley-Read-Hall recombination lifetimes in all InAs/InAsSb type-II superlattice samples are longer than 100 ns, specifically the lifetime in a long-wavelength infrared sample reaches 358 ns at 77 K, in good agreement with the previously reported result of 412 ns measured using time-resolved photoluminescence on a similar sample.