Material engineering for InAs/GaSb/AlSb quantum cascade light emitting devices

Quantum cascade lasers (QCLs) based on antimonide/arsenide heterostructures are promising candidates for room temperature high-efficiency semiconductor lasers operating in the mid-infrared (3-5/spl mu/m). The basic unit of such QCLs is made from InAs/GaSb/AlSb quantum wells (QWs) slightly strained on GaSb substrates. In this paper, we describe some key growth issues for mid-infrared electroluminescent devices based on a quantum-cascade design using InAs/GaSb/AlSb heterostructures grown on GaSb substrates. Structural and optical properties of antimonide/arsenide interfaces are first investigated on InAs/AlSb and InAs/GaSb superlattices (SL) with different types of interfaces. We use high resolution X-ray diffraction (HRXRD) to extract individual layer thicknesses.