Regensburg 2004 – scientific programme
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HL: Halbleiterphysik
HL 44: Poster II
HL 44.37: Poster
Thursday, March 11, 2004, 16:30–19:00, Poster A
Strained GaAs/InAlAs single quantum wire structures with high confinement energies — •R. Schuster1, H. Hajak1, M. Reinwald1, W. Wegscheider1, D. Schuh2, M. Bichler2, S. Birner2 und G. Abstreiter2 — 1Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany — 2Walter Schottky Institut, Technische Universität München, Am Coulombwall, 85748 Garching, Germany
Purely strain induced single quantum wires (QWRs) form where an (011) oriented quantum well (QW) is subject to lateral strain variations due to InAlAs stressor films which were introduced in the [100] direction. These structures were fabricated by molecular beam epitaxy employing the cleaved edge overgrowth technique. A systematic study of the dependence of the confinement on the widths of the overgrown and the stressor layer is carried out by using the high spectral and spatial resolution of a micro-photoluminescence setup. By reducing the the excitation power, the confinement energy can be enhanced to 51.5 meV. For all excitation powers, smooth line shapes of the photoluminescence peaks indicate the absence of pronounced exciton localization. In plane polarization is expected and observed for the light emitted by the QW, whereas the QWR signals are preferably polarized perpendicular to the QW plane. The strain distribution in these structures is numerically simulated in order to optimize the strain induced confinement. This work is supported by the Deutsche Forschungsgemeinschaft in the framework of SFB 348.