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arXiv · 1103.3935

Exciton character in picene molecular solids

Friedrich Roth·Benjamin Mahns·Bernd Büchner·Martin Knupfer
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Abstract

We have studied the low-energy electronic excitations of solid picene at 20 K using momentum dependent electron energy-loss spectroscopy. Our results demonstrate the presence of five excitonic features below the transport energy gap of picene, which all are characterized by a negligible dispersion. One of these excitons has not been observed in the optical absorption spectrum of picene molecules in solution and thus is assigned to a (solid-state induced) charge transfer exciton. This conclusion is supported by the momentum dependent intensity variation of this exciton which clearly signals a significant dipole forbidden contribution, in contrast to the other low energy excitations.

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Friedrich Roth, Benjamin Mahns, Bernd Büchner, Martin Knupfer. 2011-03-21. Exciton character in picene molecular solids. https://doi.org/10.1103/physrevb.83.165436

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