Berlin 2008 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: POSTERS Colloids, Nanoparticles and Aggregates

CPP 21.11: Poster

Wednesday, February 27, 2008, 16:00–18:30, Poster A

The role of interfaces in photoluminescence intermittency — •Cornelius Krasselt, Jörg Schuster, Harald Graaf, and Christian von Borczyskowski — TU Chemnitz, Institut für Physik, 09107 Chemnitz

Fluorescence intermittency characterized by a broad distribution of on- and off-periods, the so called power law blinking, has recently attracted great scientific interest since it appears to be a common feature of individual emitters [1]. Meanwhile it is generally accepted, that intermittency is due to the emission and trapping of charges. However, the physical nature of this charge trapping process is still unresolved and thus matter of debate. Even the most advanced available theoretical model, the diffusion controlled electron transfer model by Tang and Marcus (see references in[1]) will account for a few but not all experimental observations [1].

One of the most obvious findings is the omnipresence of interfaces in all of the observations of power law blinking reported so far, since usually various silicon oxide substrates are used as sample substrate or emitters are embedded in polymers in order to immobilize it. We show now very recent results of blinking in the presence of silicon dioxide surfaces which obviously modifies the blinking statistics. Since organic layers are knwon, to saturate interface related charge trapping centers on silicon oxides we conclude that those interface states play a key role for the blinking processes.

[1] F. Cichos, C. von Borczyskowski, M. Orrit: Curr. Op. Colloid Interface Science 12 (2007), 272