Hannover 2016 – scientific programme

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MO: Fachverband Molekülphysik

MO 16: Molecular Clusters

MO 16.3: Talk

Thursday, March 3, 2016, 12:00–12:15, f142

Fluorescence lifetime reduction of organic semiconductors attached to the surface of solid neon cluster — •sharareh izadnia, markus müller, aaron laforge, and frank stienkemeir — Physikalisches Institut, Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany

The collective emission of coherent light is a fundamental process in quantum mechanics. The resulting radiation leads to effects such as superradiance. One particularly fascinating manifestation of superradiance is the process of spontaneous coherent emission of light by an ensemble of identical excited atoms, which was initially predicted by Dicke [1]. Superradiance has been observed almost universally in weakly interacting systems such as hot dense gases [2]. Here, we report the experimental observation of fluorescence lifetime reduction of tetracene by directly tuning the number of molecules attached to the surface of neon clusters and excitation laser power. For average intermolecular distances greater than 33 Å, we attribute the reduction in fluorescence lifetime to Dicke superradiance [3], while for smaller intermolecular distances, additional lifetime reduction occurs due to the onset of non-radiative de-excitation (e.g. singlet fission).

[1] R. H. Dicke, Phys. Rev. 93, 99 (1954).

[2] N. Skribanowitz, I. P. Herman, J. Macgilli, and M. S. Feld, Phys.Rev. Lett. 30, 309 (1973).

[3] M. Müller, S. Izadnia, S. M. Vlaming, A. Eisfeld, A. LaForge and F. Stienkemeier. Phys. Rev. B 92, 121408(R) (2015)