Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 37: Quantum Dots and Wires: Optical Properties I (mainly InGaAs Dots)
HL 37.8: Vortrag
Dienstag, 27. März 2012, 12:30–12:45, ER 164
Sharp luminescence from a site-controlled single quantum dot — •Ole Hitzemann1, Alexander Dreismann1, Erik Stock1, André Strittmatter1, Andrei Schliwa1, Jan-Hindrik Schulze1, Tim D. Germann1, Waldemar Unrau1, Udo W. Pohl1, Axel Hoffmann1, Dieter Bimberg1, and Vladimir Haisler2 — 1Institut für Festkörperphysik, Technische Universität Berlin, Germany — 2Institute of Semiconductor Physics, Russian Academy of Sciences, Novosibirsk, Russian Federation
Site-controlled growth of single quantum dots (QDs) is essential for applications such as single-photon sources. We investigate InGaAs QDs grown by metal organic vapor phase deposition using a buried stressor for lateral positioning. The buried stressor is formed by controlled partial oxidation of an AlGaAs layer to create an AlOx aperture as it has been used previously for current-confinement in vertical-cavity surface emitting laser diodes. The oxidation reduces the volume of this layer thus inducing strain in adjacent GaAs layers. The QDs are grown on a GaAs surface 150 nm above the oxide layer but the nucleation sites are controlled by the inner boundaries of the oxide aperture.
Using a sub-micrometer oxide aperture we observe only luminescence from a single QD within a 60 meV spectral range. The observed luminescence consists of a doublet of two lines that are 80 µeV apart with a full width at half maximum of 80 µeV each, limited by the spectral resolution of the setup. In autocorrelation measurements using a Hanbury-Brown Twiss setup we demonstrate an antibunching thus proving emission from a single QD.