Dresden 2017 – wissenschaftliches Programm
HL 36.7: Vortrag
Dienstag, 21. März 2017, 11:30–11:45, POT 251
Strongly reduced inhomogeneous broadening of molecular aggregates in hybrid nanostructure system — •Xuan Trung Nguyen1, Antonietta De Sio1, James Lim2, Alexandra Markovic3, Julia Witt3, Gunther Wittstock3, Susana Huelga2, Martin Plenio2, and Christoph Lienau1 — 1Institut für Physik, Carl von Ossietzky Universität Oldenburg, Germany — 2Institut für Theoretische Physik and IQST, Universität Ulm, Germany — 3Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Germany
The applications of nanostructures based on organic molecular aggregates range from solar cells to all-optical switching. These aggregates are often modeled as disordered systems that exhibit inhomogeneously broadened absorptive line shapes. In such a system, disorder localizes the exciton wavefunction and leads to limited exciton transport efficiency, which is important in devices like solar cells. By using linear and non-linear spectroscopy, we show that the inhomogeneous broadening of a model J-aggregate cyanine dye is strongly reduced in the presence of an ultrathin gold layer and the resulting optical spectra display almost perfect Lorentzian line shapes. Supported by theoretical simulations, we explain the experimental results in terms of increased delocalization of the exciton wavefunction due to electronic coupling to surface plasmon polaritons supported by the aggregate-gold. This coupling can average out the disorder effect and thus increase the exciton transport efficiency.