Photoreflectance of GaSb/Al0.4Ga0.6Sb single quantum wells

We report a photoreflectance study conducted in the 0.7–1.2 eV photon energy range and at temperatures from 80 to 300 K of GaSb/Al0.4Ga0.6Sb single quantum wells grown by molecular beam epitaxy. We observed clear and well-resolved structures, which could be attributed to the interband optical transitions originating in both the GaSb buffer and the quantum wells, and which could be fitted by standard critical-point line shapes. Our results demonstrate that even unintentionally doped GaSb-based quantum systems can be studied and characterized by photoreflectance, especially at low temperatures.