Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 13: Quantum Dots and Wires: Preparation and Characterization I

HL 13.6: Vortrag

Montag, 22. März 2010, 15:15–15:30, H17

Site Controlled InAs Quantum Dots with ultra low densities and improved spectral uniformity — •Carmen Drescher, Christian Schneider, Kousha Talebian, Martin Kamp, Sven Höfling, Stefan Reitzenstein, Lukas Worschech, and Alfred Forchel — Technische Physik,Physikalisches Institut, Universität Würzburg and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg,Am Hubland, 97074 Würzburg, Germany

In order to exploit InAs Quantum Dots (QDs) coupled to microcavities as single photon sources in a scalable manner one needs to know the exact position of the QD for device alignment. To improve the yield of spectrally resonant devices without adjusting the resonator geometry to the individual QD emission wavelength it is necessary to reduce spectral inhomgeneities in the ensemble emission of the QD array. The position control of our site controlled QDs (SCQDs) is maintained by directing the QD nucleation to shallow etched nanoholes on a (1,0,0) GaAs surface. To achieve a reasonably low single QD linewidth and ensemble broadening, growth parameters during the molecular beam epitaxy (MBE) deposition step of the QDs have been optimized and investigated. We have monitored the influence of the substrate temperature during SCQD growth as an important parameter for spectral homogeneity and achieved accurate QD nucleation of single SCQDs on pitches up to 4 μm on both uncapped and buried SCQDs.