Berlin 2015 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 9: Quantum dots: Optical properties

HL 9.5: Vortrag

Montag, 16. März 2015, 11:00–11:15, EW 203

Exciton dynamics in a single site-controlled quantum dot — •Ole Hitzemann, Andrei Schliwa, André Strittmatter, Jan-Hindrik Schulze, David Quandt, Waldemar Unrau, Udo W. Pohl, and Axel Hoffmann — Institut für Festkörperphysik, Technische Universität Berlin, Germany

Direct and phonon-mediated channels of optical excitation are studied on a single isolated site-controlled InGaAs/GaAs quantum dot (QD). The nucleation site was precisely defined by a distant buried stressor formed by controlled partial oxidation of a sandwiched AlGaAs layer as part of a mesa structure.

Above a sub-micrometer aperture we observe sharp luminescences lines, originating from a single QD as demonstrated by autocorrelation measurements. Micro photoluminescence excitation spectroscopy shows and coupling with phonon modes as well as distinctively different photoluminescence spectra for different excitation energies. Excitation power dependent measurements reveal the saturation behavior of excitonic and high excitation luminescence lines. The decay dynamics of different exciton related luminescence lines are studied by time-resolved micro photoluminescence spectroscopy.