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CPP: Chemische Physik und Polymerphysik

CPP 30: POSTER: Chemical physics

CPP 30.37: Poster

Tuesday, March 8, 2005, 16:30–18:30, Poster TU D

Photophysics of Single Supramolecular Aggregates of Semiconductor Nanoparticles and Organic Molecules — •Thomas Blaudeck and Frank Cichos — Photonics and Optical Materials, Institute of Physics, TU Chemnitz, 09107 Chemnitz, Germany

We report on elementary interaction processes in aggregates of self-organized thiol-end-capped organic molecules and semiconductor nanoparticles (NPs). In the regime of strong coupling between individual NPs, delocalization of the electronic states across multiple NPs leads to new states and yields a change of optical and electronic properties by environment. In this respect, steady-state spectroscopy of CdSe NPs in solution shows significant red-shifts of the band-edge exciton in both absorption and emission spectra as the concentration of 1,4-Benzenemethanethiol (BDMT) is increased. This fact is interpreted as an indication for the aggregation process. Photoluminescence of the aggregates reveals a spectral variation correlated with size. We also present results on the single-particle scale approached by confocal microscopy, spectroscopy and time-correlated single-photon counting (TCSPC).