Dresden 2011 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

SYMN: Intersectional Symposium Transport and Spectroscopy in Molecular Nanostructures

SYMN 1: Transport and Spectroscopy in Molecular Nanostructures

SYMN 1.1: Hauptvortrag

Mittwoch, 16. März 2011, 10:30–11:00, HSZ 01

Exciton localization and dynamics in molecular aggregates — •Jasper Knoester — Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands

Self-assembled aggregates of dye molecules are interesting nanoscale systems with a variety of morphologies and dimensionalities in which energy transport and optical properties are governed by Frenkel excitons. The latter are collective electronic excitations, the extent of which is determined by the interplay between intermolecular excitation transfer interactions within the aggregate and the interaction with other degrees of freedom (static disorder and vibrations). The interest in these systems results from their strong interaction with light, their often sharp and color-tunable absorption bands, and their fast energy transport. In this talk, I will address recent results on exciton localization and dynamics in linear and tubular molecular aggregates, and the associated spectral signatures. I will discuss the model of delocalized excitons weakly scattered on vibrations, which has allowed good comparison to experiments for a variety of properties and systems. I will also address surprising properties of linear exciton systems with diagonal disorder taken from distributions with divergent second moments (Levy disorder). Finally, I will go beyond the picture of weak exciton-vibration interaction by explicitly including vibronic effects, thus addressing the dynamics of exciton-polarons. Various spectroscopies, such as absorption, linear and circular dichroism, and two-dimensional correlation spectroscopy, will be discussed.