Fast luminescence in silicon-germanium nanostructures

Epitaxially-grown three-dimensional Si/SiGe nanostructures produce photoluminescence and electroluminescence in the desired spectral range of 1.3-1.6 μm. We show that by controlling and modifying such Ge-rich SiGe nanoclusters during growth it is possible to fabricate very fast and hence more efficient SiGe light-emitting devices. The physics of carrier recombination in these Si/SiGe nanostructures is discussed. The present results provide another possible route toward CMOS compatible light emitters.