Dresden 2011 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 53: Optical Properties I
HL 53.2: Talk
Wednesday, March 16, 2011, 12:45–13:00, POT 251
Many-body effects in phonon-sideband luminescence — •Alexej Chernikov1, Verena Bornwasser1, Christoph N. Böttge1, Thomas Feldtmann1, Sangam Chatterjee1, Martin Koch1, Mackillo Kira1, Stephan W. Koch1, Thomas Wassner2, Stefan Lautenschlaeger2, Bruno K. Meyer2, and Martin Eickhoff2 — 1Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany — 2I. Physikalisches Institut,Justus-Liebig-Universität Giessen,Heinrich-Buff-Ring 16, D-35392 Giessen, Germany.
The photoluminescence spectra of high-quality intrinsic semiconductors with a direct bandgap are usually dominated by the excitonic resonance. The spectra may also feature one or more additional lines, commonly referred to as phonon sidebands (PSBs), traced back to the phonon-assisted recombination. In theory, PSB luminescence is traditionally treated using a perturbative approach with excitons coupled directly to LO-phonons via polar Froehlich interaction. However, the many-body properties of the interacting carrier system yield a more complex picture. Already the luminescence at the main excitonic resonance does not necessarily require excitonic population. In addition, the Froehlich coupling is expected to be suppressed in case of the exciton-phonon interaction. Here, we study the time-resolved PSB emission of direct polar semiconductors and apply a microscopic many-body approach to analyze the experimental observations. Our results show that excitonic population is not required for the observation of PSBs.