Darmstadt 2008 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 2: Elektronische Spektroskopie
MO 2.6: Vortrag
Montag, 10. März 2008, 17:45–18:00, 3F
Transfer processes in organic donor-acceptor dyads containing tetraphenylbenzidine and perylenebisimide studied by time-resolved spectroscopy — •Christiane Hofmann1, Peter Bauer2, Mukundan Thelakkat2, and Jürgen Köhler1 — 1Department of Experimental Physics IV and BIMF, University of Bayreuth, D-95440 Bayreuth, Germany — 2Applied Functional Polymers, University of Bayreuth, D-95440 Bayreuth, Germany
We investigated transfer processes in organic donor-acceptor dyads by time-resolved fluorescence spectroscopy. In the dyads, perylenebisimide (PBI) is covalently linked to a tetraphenylbenzidine (TPD) unit by a spacer. TPD acts as an energy transfer donor, PBI as an acceptor. Fluorescence lifetimes of both TPD and PBI have been determined for three different types of spacer and as a function of the solvent. We found that changing the spacer length had a significant influence on the TPD lifetime and on energy transfer efficiency. For all three TPD-PBI dyads the PBI lifetimes were considerably shorter than those measured for pure PBI and varied significantly upon changing the chemical composition of the spacer. We could also show that the PBI lifetimes depend noticeably on the solvent. Particularly, we found a correlation between the acceptor decay rate and the rotational diffusion time constant, which in turn is a function of the local viscosity of the solvent.