Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 39: Quantum dots: Optical and transport properties

HL 39.2: Vortrag

Donnerstag, 26. März 2009, 09:45–10:00, BEY 81

Experimental realization of a spectrally resonant site-controlled quantum dot-micropillar cavity system — •Alexander Huggenberger, Christian Schneider, Tobias Heindel, Pia Weinmann, Caroline Kistner, Martin Kamp, Stephan Reitzenstein, Sven Höfling, and Alfred Forchel — Technische Physik, Universität Würzburg, Germany

We present a technology for the integration of site-controlled InAs quantum dots (QD) into GaAs/AlAs micropillar cavities in a spatially deterministic manner. QD formation at pre-defined positions is forced by patterning nano-holes as nucleation centres. The sample layout enabling the site-controlled growth of the QDs and retrieving them by cross markers for the incorporation into micro-pillars cavities are discussed. A combination of morphological studies like scanning electron microscopy and atomic force microscopy characterization is used to establish a fabrication process to precisely control the QD position for device integration. The emission of single QDs is probed by microPL spectroscopy and reveals clear spectra with single lines. An advanced technique has been developed to improve the optical quality of single site-controlled quantum dots. Vertically stacked but different sized and therefore spectrally detuned site-controlled QD layers have been grown. This allows for the selective interaction between only one single QD emission line and a cavity mode in the cavity quantum electrodynamics regime. By temperature tuning of the QD emission into resonance with the cavity mode an enhanced spontaneous emission is observed, thus demonstrating a site-controlled QD-micropillar cavity system.