Optical properties of self-assembled Ge(Si) quantum dots grown on Si(001) by molecular beam epitaxy

We report the Raman, continuous-wave (CW) photoluminescence (PL) measurements of Ge(Si)/Si samples with an islands like morphology. The values of composition and elastic deformation of the self-assembled Ge(Si) nanoislands formed at 550degC were determined by Raman scattering spectroscopy. Due to larger islands size, and intermixing of Si and Ge, the PL peak is red shifted for longer time deposition of Ge. The observed broad PL signal from Ge(Si) islands is associated with radiative recombination of holes confined in the Ge(Si) islands and electrons localized in the Si layer.