Inhomogeneous linewidth broadening of exitonic transistions in a quantum well system is governed, in part, by interface roughness, and lateral variations of strain and barrier composition. The effect of these parameters on the excitonic linewidth were investigated using in-plane atomic force microscopy, high resolution x-ray diffraction and transmission Fourier transform infrared spectroscopy. This was carried out by studying growth uniformity on several nominally undoped InSb/AlInSb multiple quantum well samples grown on semi-insulating GaAs substrates by molecular beam epitaxy. The main features of topographical scans are hillocks and oriented abrupt steps initiated at the substrate/growth interface and square mounds and probably originating at the AlInSb/buffer layer interface. The influence of these features on the exitonic linewidth broadening will be discussed.
