Dresden 2011 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 57: ZnO: Optical Properties
HL 57.4: Talk
Wednesday, March 16, 2011, 15:15–15:30, POT 151
Emission Properties of ZnMgO/ZnO Quantum Wells — •Pascal Becker1, Bernhard Laumer1,2, Fabian Schuster2, Martin Eickhoff1, and Detlev M. Hofmann1 — 1I. Physikalisches Institut, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen — 2Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching
ZnO quantum wells embedded in Zn(1−x)MgxO barriers are possible candidates for the realization of light emitters in the blue and near UV spectral range and exhibit interesting optical properties due to the presence of spontaneous and piezoelectric polarisation fields, which give rise to the quantum confined Stark effect. Here, we investigated MBE-grown ZnO quantum wells with different thickness and barrier composition x by luminescence and magneto-optical spectroscopy. The properties of wide quantum wells (> 5nm) are in good agreement to published data. However, for narrow quantum wells we observe an opposite sign of the magnetic circular polarisation of the emission (MCPE) and an inverted slope of the magnetic field dependence. We will discuss this effect in terms of changes in the valence band ordering.