We have recently found that high quantum efficiency can be achieved in strained Si1-xGex alloy layers through the elimination of nonradiative channels. We observed a photoluminescence process in SiGe grown on 〈100232A; silicon by rapid thermal chemical vapor deposition, which was attributed to free excitons localized by random fluctuations in alloy composition. The external quantum efficiency of this process was measured directly for a single Si0.75Ge0.25 quantum well and found to be extraordinarily high, about 11.5 ± 2%. In this paper, we present additional data on the localized exciton photoluminescence, including temperature dependence, time decay curves, and effects of sample annealing.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry
- Localized excitons
- photoluminescence spectroscopy