Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 9: POSTERS Single Molecules, Biopolymers, Membranes

CPP 9.3: Poster

Montag, 25. Februar 2008, 16:45–19:00, Poster A

Blinking induced bleaching and recovery of organic dyes in polymer materials — •Ines Trenkmann, Jörg Brabandt, Jörg Schuster, and Christian von Borczyskowski — TU Chemnitz, Institut für Physik, 09107 Chemnitz

Fluorescence intermittency, usually referred to as blinking, is a common feature of individual emitters embedded into or close to dielectric materials such as polymers or silicon oxides [1]. If the photoluminescence from ensembles of emitters is observed under conditions similar to single emitter studies, blinking processes lead to a reversible change of the intensity, which is in most cases a decrease of intensity [2]. Such reversible intensity decays and its recovery have been studied by us for ensembles of different dye/polymer systems. Our preliminary results show, that the kinetics of the fluorescence recovery is rather a function of the matrix than of the emitter. While fluroescence recovery of dyes in PVA occurs on a time scale of seconds it takes several hours to days in polystyrene. Based on those findings and recent publications [1] the model of blinking as a process of ejecting and trapping of charges in dielectric materials gains further evidence. In conclusion, we suggest to use blinking vive versa as a probe for charge trapping in dielectric properties. Our results show, that blinking phenomena can be studied easily on the ensemble level by bleaching and recovery experiments.

[1] F. Cichos, C. von Borczyskowski, M. Orrit: Curr. Op. Coll. Interf. Sc. 12 (2007), 272

[2] J. Brabandt, J. Schuster, C. von Borczyskowski: J. Luminescence 127 (2007),224