Carrier loss mechanisms in type II quantum wells for the active region of GaSb-based mid-infrared interband cascade lasers

Thermal quenching of photoluminescence has been measured for InAs/GaInSb broken gap system quantum wells as a function of the thickness of the conduction and valence band wells. The primary activation energy appears too small for the electrons to leave the well, and insensitive to even significant changes in the InAs layer thickness and hence electron confinement potential. On the contrary, it varies strongly with the modification of the confinement of holes in the GaInSb layer. Thus, tunneling-assisted escape of holes into the GaSb layers has been recognized as the dominant carrier loss mechanism in these type II quantum wells. (C) 2011 Elsevier B.V. All rights reserved.