Dr. Sebastian Hartweg

Sebastian is involved in several projects in the molecular and nanophysics group of Prof. Stienkemeier. Some of these projects are concerning organic chromophore molecules, their electronic structure and excited-state dynamics and how these properties are affected by cluster formation and environment effects. The excited state dynamics and de-excitation pathways of such molecules are known to change drastically when changing from isolated molecules in the gas phase to small clusters, larger aggregates or to the condensed phase, where electronic interactions between neighboring molecules have to be considered. Within these projects different spectroscopic techniques like photoelectron or fluorescence spectroscopy using table-top nanosecond and femtosecond laser systems are applied to chromophore molecules in different environments. The systems studied range from isolated molecules in effusive or supersonic molecular beams to molecules and their aggregates isolated on rare gas clusters or in liquid helium nanodroplets.

Furthermore, Sebastian is involved in research on various atomic, molecular and cluster systems using intense XUV pulses from the free electron laser Fermi. Among the processes studied are electronic relaxation and molecular fragmentation processes following optical excitation, single or multiple photoionization of small molecules and clusters.