PhD ceremony Mr. E.A. Bloemsma: Exciton localization and optical spectroscopy of linear and tubular J-aggregates

PhD ceremony: Mr. E.A. Bloemsma, 14.30 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Exciton localization and optical spectroscopy of linear and tubular J-aggregates

Promotor(s): prof. J. Knoester

Faculty: Mathematics and Natural Sciences

Molecular J-aggregates are large self-assembled structures that may contain up to thousands of molecules. These aggregates can be found in natural photosynthetic systems of bacteria and plants, where they play a key role in the light-harvesting and energy transport processes.

The excitations in such systems are typically shared by many molecules, owing to the strong intermolecular interactions, resulting in a collective optical response of the aggregate. Based on theoretical models, we have studied the collective behavior of excitations in aggregates of various geometries and their relation to the optical properties.

Topics of special interest are the effects of the aggregate’s local surroundings on the collective nature of the excitations, the way in which the specific arrangement of the molecules in the aggregate determines the optical features in the absorption spectrum, the consequences of interactions between two molecular aggregates in close proximity, and the role of multi-exciton states in single-molecule spectroscopy.