Photoluminescence characterization of SiGe QW grown by MBE

Photoluminescence (PL) emission spectra have been carried out on a partially relaxed Si/Si1-xGex/Si quantum well (QW) grown by solid-source MBE at a nominal composition of x = 17%, The results are discussed in terms of the film morphology, as derived from structural techniques (SEM, RHEED, RES and XRD): especially as regards the presence of a high density of dots-like 3D structures. PL spectra show an intense brood band, attributed to excitonic recombinations at interstitial plateletes in the dots, with smaller X-NP and X-TO excitonic lines due to phonon-resolved interband transitions originated from the strained epitaxyal layer grown before the dot formation