Berlin 2012 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 8: Poster: Nanoparticles and Composite Materials

CPP 8.42: Poster

Montag, 26. März 2012, 17:30–20:00, Poster A

Tailoring the blinking behaviour of single CdSe/ZnS nanoparticles — •Daniel Braam, Andreas Mölleken, Günther M. Prinz, Martin Geller, and Axel Lorke — Fakultät für Physik and CeNIDE, University of Duisburg-Essen, Lotharstraße 1, 47057 Duisburg, Germany

Though CdSe/ZnS nanoparticles have been investigated over the last decades, their emissive behaviour still lacks a complete understanding. Single particle photoluminescence (PL) measurements have the ability to give insight into the underlying recombination processes. With a custom-built µ-PL setup, using a LN₂ cooled CCD-camera attached to an imaging spectrometer, we can aquire time-resolved 2D-images of several nanoparticles to investigate them and their blinking statistics simultaneously. Specific particles can be selected for further spectral characterisation. Here, we focus on the influence of different rough metal layers on the brightness and stability of the luminescence. We observe intensity enhancement, which we attribute to plasmonic effects, and continuous blue shifts of several tens of nanometers during illumination, which is accompanied by randomly varying stark shifts. At low temperatures (≤10 K) some particles show spectral jumps of 25 meV instead of blinking, which indicate altered radiative and nonradiative recombination rates induced by the aluminium layer.