Dresden 2014 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 63: Invited Talk Axel Hoffmann
HL 63.1: Hauptvortrag
Mittwoch, 2. April 2014, 12:00–12:30, POT 006
Exciton-phonon coupling in nitride-based nanostructures — G. Callsen1, G. Hönig1, S. Kalinowski1, J. Settke1, C. Kindel1, J. Brunnmeier1, T. Markurt2, M. Albrecht2, S. Kako3, A. Schliwa1, Y. Arakawa3, and •A. Hoffmann1 — 1Technical University of Berlin, 10623 Berlin, Germany — 2Leibniz Institute for Crystal Growth (IKZ), 12489 Berlin, Germany — 3University of Tokyo, Tokyo 153-8505, Japan
We review the exciton-phonon coupling in nitride-based nanostructures such as e.g. GaN/AlN quantum dots (QDs). Generally, nanostructures based on strongly polar group III-nitrides represent ideal candidates for analyzing the exciton-phonon interaction in contrast to only weakly polar materials as e.g. the group III-arsenides. Occurring large excitonic dipole moments inherent to nitride QDs facilitate an efficient coupling to acoustical and optical phonons, clearly observable in μPhotoluminescence spectra. We reveal a strong QD size and geometry dependence of the Huang-Rhys factor, as a measure of the exciton-LO-phonon coupling strength, and the LO-phonon energy, based on a unique conjunction of experimental and theoretical results. The given observation can be regarded as general phenomena in strongly polar nanostructured materials and highlight current limitations in regard to applications at non-cryogenic temperatures.