GaInN quantum well design and measurement conditions affecting the emission energy S-shape

C. Netzel¹, S. Hatami¹, V. Hoffmann¹, T. Wernicke^1,2, A. Knauer¹, M. Kneissl^1,2 and M. Weyers¹

¹ Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
² Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany

Published in:
phys. stat. sol. (c), vol. 8, no. 7-8, pp. 2151-2153 (2011).
© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Abstract:
Polarization fields and charge carrier localization are the dominant factors defining the radiative recombination processes in the quantum wells of most AlGaInN-based optoelectronic devices. Both factors determine emission energy, emission line width, recombination times, and internal quantum efficiency. For a deeper understanding of the charge carrier recombination processes, we have performed temperature and excitation power dependent photoluminescence experiments on epitaxially grown GaInN structures to study the S-shape of the temperature dependent emission energy.
The S-shape behaviour in GaInN quantum wells (QWs) is dominated by the temperature dependence of the charge carrier localization. However, in polar QWs it is strongly affected by the charge carrier density which screens the piezoelectric field. External applied fields change the observable S-shape characteristic significantly. Semi- and nonpolar GaInN QWs feature an Sshape behaviour which points to much stronger charge carrier localization compared to polar QWs.

Keywords:
GaInN, quantum wells, S-shape, localization, piezoelectric field

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