Showing papers by "Masao Nishioka published in 2011"

Metal Organic Chemical Vapor Deposition Growth of High Spectral Quality Site-Controlled InAs Quantum Dots Using In situ Patterning

Abstract: We present a promising method for the fabrication of high-quality InAs site-controlled quantum dots (QDs) by combining electron beam lithography with wet chemical etching and metalorganic chemical vapor deposition (MOCVD) in situ patterning. The (100) GaAs substrate is patterned with nanoholes by thermal etching and the dots are directly grown inside. This method should avoid the introduction of the surface defects that occurs usually with standard lithography techniques. The thermal etching time is a new growth parameter used to control the shape and size of the QDs. The optical characterization at low temperatures reveals QDs with a small linewidth down to 63 µeV.

Effect of Antimony on the Photoluminescence Intensity of InAs Quantum Dots Grown on Germanium-on-Insulator-on-Silicon Substrate

Abstract: We report on the antimony (Sb) surfactant-mediated growth of InAs quantum dots (QDs) on a germanium-on-insulator-on-silicon (GeOI) substrate A GaAs buffer layer of high structural quality and low surface roughness was first grown on a GeOI substrate The dependence of Sb irradiation time on the photoluminescence intensity and total density of InAs/Sb:GaAs QDs grown on a GeOI was studied High density (above 6×1010 cm-2) QDs with ground state emission in the 13 µm band at room temperature and narrow linewidth (32 meV) was obtained Together, these results are very promising for potential realization of monolithically integrated QD-based lasers on silicon