Regensburg 2010 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 36: Poster: Nanoparticles and Composite Materials

CPP 36.17: Poster

Mittwoch, 24. März 2010, 17:30–19:00, Poster B2

Time resolved spectroscopy and lifetime measurements of single semiconductor nanocrystals — •Robert Schmidt, Cornelius Krasselt, and Christian von Borczyskowski — TU Chemnitz, Institute of Physics, Department of Optical Spectroscopy and Molecular Physics (OSMP), nanoMA (Center for nanostructured Materials and Analytics)

The photoluminescence of single emitters like semiconductor quantum dots (QDs) shows intermittency, called blinking, which divides the intensity time traces into bright "on"-, dark "off"-and intermediate-states. The distribution of "off"-times shows power law behavior with an exponential decay. While the power law behavior of "off"-times is well understood, it is less evident for "on"-times.

We investigate the blinking-dynamics of CdSe/ZnS-nanocrystals using time resolved confocal microscopy, spectroscopy and lifetime measurements. The intensity time traces are analysed with special focus on intermediate intensities, by varying the threshold separating the on- and off- from intermediate-states. Further the intensity time traces are compared with spectral- and lifetime- time traces in order to obtain correlations between intensities, lifetimes and spectral positions. We will report new insights into the intrinsic dynamics of QD.