Molecular beam epitaxy growth of high-quality, lattice-matched InAsSb on GaSb substrates

We grew lattice-matched InAsSb on GaSb substrates using molecular beam epitaxy (MBE). The effects of growth rate, As and Sb beam fluxes were systematically investigated by high-resolution X-ray diffraction (HRXRD), elucidating the relationship between growth parameters and Sb composition. These optimized growth parameters were validated by fabricating a high-quality, 7-period InAs/InAsSb multiple quantum well (MQW) structure on a GaSb substrate. The resulting MQW structure exhibited XRD satellite peaks up to the +9th order, indicating good periodicity and structural quality. The Sb composition of the InAsSb layer was determined to be approximately 8.9 %, with a thickness deviation of only +0.2 %. A slight angular offset observed between the zeroth-order MQW peak and the GaSb substrate is attributed to slight tensile strain from the thin InAs layers. These results are consistent with the growth of a high-quality, nearly lattice-matched structure. This study provides experimental guidelines for growing high-quality InAsSb layers and superlattices, which are essential for the development of next-generation mid-infrared laser sources, detectors and other optoelectronic devices.