TY  - JOUR
A1  - Dostál, Jakub
A1  - Fennel, Franziska
A1  - Koch, Federico
A1  - Herbst, Stefanie
A1  - Würthner, Frank
A1  - Brixner, Tobias
T1  - Direct observation of exciton–exciton interactions
T2  - Nature Communications
N2  - Natural light harvesting as well as optoelectronic and photovoltaic devices depend on efficient transport of energy following photoexcitation. Using common spectroscopic methods, however, it is challenging to discriminate one-exciton dynamics from multi-exciton interactions that arise when more than one excitation is present in the system. Here we introduce a coherent two-dimensional spectroscopic method that provides a signal only in case that the presence of one exciton influences the behavior of another one. Exemplarily, we monitor exciton diffusion by annihilation in a perylene bisimide-based J-aggregate. We determine quantitatively the exciton diffusion constant from exciton–exciton-interaction 2D spectra and reconstruct the annihilation-free dynamics for large pump powers. The latter enables for ultrafast spectroscopy at much higher intensities than conventionally possible and thus improves signal-to-noise ratios for multichromophore systems; the former recovers spatio–temporal dynamics for a broad range of phenomena in which exciton interactions are present.
KW  - energy transfer
KW  - self-assembly
KW  - optical spectroscopy
Y1  - 2018
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/22627
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-226271
VL  - 9
ER  -