Strong photoluminescence at 1.53 mu m from GaSb/AlGaSb multiple quantum wells grown on Si substrate

Abstract

Strong photoluminescence at 1.53 mu m was obtained from a GaSb/Al0.4Ga0.6Sb multiple-quantum-well sample grown on Si substrate, indicating greatly reduced defects by InSb quantum-dot layers that terminate dislocations. The carrier lifetime of 1.4 ns, comparable to typical InP-based quantum wells, and its independence on excitation power indicates the low defect density. Due to the wide well width and tensile strain, photoluminescence was dominated by the light hole-electron transition at low temperature. However, the heavy hole-electron transition was dominant at room temperature due to the proximity of energy levels and higher density of states for the heavy hole transition.