Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 37: Quantum Dots and Wires: Optical Properties III
HL 37.12: Vortrag
Mittwoch, 24. März 2010, 12:30–12:45, H15
Excited state spectroscopy of single lateral InGaAs quantum dot molecules — •Matthias Heldmaier1, Claus Hermannstädter1, Marcus Witzany1, Jie Peng2, Gabriel Bester2, Lijuan Wang3, Armando Rastelli3, Oliver G. Schmidt3, and Peter Michler1 — 1Institut für Halbleiteroptik und Funktionelle Grenzflächen, Allmandring 3, 70569 Stuttgart, Germany — 2Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany — 3Institut für Integrative Nanowissenschaften IFW Dresden, Helmholtzstraße 20, 01069 Dresden, Germany
The investigated structures contain self-assembled laterally coupled InGaAs quantum dots embedded in a planar microcavity, which are grown using a combination of metal-organic vapor phase and molecular beam epitaxy. The individual quantum dot molecules (QDMs) consist of two single dots that are coupled along the [1-10] crystal direction via electron tunneling. The coupling strength and the ground and excited state energies of the QDMs can be manipulated by applying a lateral electric field. A change in the relative intensities of the excitonic emission lines is observed in the photoluminesence (PL) spectra. PL excitation measurements were conducted using a wide-range tunable Ti:Sapphire laser to obtain information about excited states confined in the QDM. The results of these measurements are compared with the energies of the single-particle and correlated exciton states in the system obtained by an empirical pseudo-potential calculations using a random composition of the QDMs.