Growth and characterization of Ge islands on Si(1 1 0)

The structural and optical properties of self-assembled Ge dots grown on Si(1 1 0) substrates by low pressure chemical vapour deposition have been studied. A monomodal island size distribution with multifaceted domes has been determined from an atomic force microscopy characterization. An analysis of the island size provided information on the strain in islands. Thus, dome shape islands appear on our samples as elastically relaxed. Photoluminescence spectroscopy investigations as a function of temperature and excitation power allowed to identify two broad lines, which are respectively attributed to the wetting layer and the islands emissions. A good hole confinement allowing excitonic recombinations has also been pointed out.