Time-resolved photoluminescence of pseudomorphic SiGe quantum wells

We report low-temperature time-resolved photoluminescence experiments on a pseudomorphic SiGe quantum-well structure. Under the condition of optical absorption in the Si buffer layers, the decay time of the SiGe quantum-well luminescence is controlled by the capture of excitons and electron-hole droplets. From the onset of the SiGe luminescence, the exciton lifetime in the investigated 59 - wide Si0.72Ge0.28 quantum wells is found to be about 100 ns.