Design of 3.3 and 4.2 μm mid-infrared metamorphic quantum well light-emitting diodes

The use of Al_zIn_1-zAs metamorphic buffer layers to facilitate the growth of lattice-mismatched InN_y(As_1-xSb_x)_1-y quantum wells on GaAs or InAs substrates has recently been demonstrated to constitute an attractive approach to developing light-emitting devices at application-rich mid-infrared wavelengths. However, little information is available regarding the fundamental properties of this newly established platform. We present a theoretical investigation and optimisation of the properties and performance of InN_y(As_1-xSb_x)_1-y/Al_zIn_1-zAs structures designed to emit at 3.3 and 4.2 μm. We quantify the design space available to these structures in terms of the ability to engineer and optimise the optoelectronic properties, and quantify the potential of metamorphic InN_y(As_1-xSb_x)_1-y structures for the development of mid-infrared light emitters, providing guidelines for the design of optimised light-emitting diodes.