Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 77: Quantum Dots and Wires: Optical Properties II (mainly Luminescence and Electronic Structure)
HL 77.5: Talk
Thursday, March 29, 2012, 10:30–10:45, EW 203
Size dependent excitonic states in self-assembled GaAs quantum dots: theory and experiment — •Andreas Graf1, David Sonnenberg1, Vera Paulava1, Andrei Schliwa2, Christian Heyn1, and Wolfgang Hansen1 — 1Institut für Angewandte Physik, Universität Hamburg, 20355 Hamburg, Germany — 2Institut für Festkörperphysik, Technische Universität Berlin, 10623 Berlin, Germany
Local droplet etching (LDE) allows for a molecular beam epitaxy compatible self-assembled patterning of semiconductor surfaces. Using LDE with aluminium droplets, nanoholes with 12 nm depth are drilled in AlAs capped AlGaAs layers. Partial filling of these nanoholes with GaAs provides quantum dots (QD) with a precisely defined size. We present photoluminescence measurements of single GaAs QDs. The QD size dependent exciton and biexciton recombinations and in particular the splitting of exciton and biexciton peaks are studied. Calculations based on k·p theory and configuration interaction scheme were performed, in order to investigate the general behavior of the excitonic states in GaAs QDs as well as the influence of QD size. The comparison between measured and calculated recombination energies and intensities demonstrates good agreement.