Time-Resolved Spectroscopy
Dynamics of π-conjugated molecules and their dimers with picosecond radiation
This project focuses on polycyclic aromatic hydrocarbons (PAH) and their nitrogen-containing counterparts (PANH). These molecules often possess photophysical properties, that make them potentially interesting for application in optoelectronic materials. We study the processes that occur in these molecules and their dimers after photoexcitation. The experiments are carried out in the gas phase in order to investigate the intrinsic properties of the molecules and dimers, without perturbation by a solvent. The results are subsequently compared with simulations performed in the group of Roland Mitric. In the dimers we focus on better understanding energy transfer processes and excimer formation in aggregates. Time-resolved spectroscopy in the picosecond (ps) range is used as an experimental method. We have established time-resolved photoelectron spectroscopy as a detection method, which we couple with modern imaging detection methods. This allows more detailed insights into the light-induced dynamics.
Femtosecond Spectroscopy
When necessary, we carry out experiments with femtosecond time resolution in cooperation with the group of L. Poisson (CEA Saclay near Paris). supported by the Laserlab Europe program (https://www.laserlab-europe.eu/). Our preferred methods are time-resolved photoionisation and photoelectron spectroscopy.
Recent publications:
1. Joscha Hoche, Marco Flock, Xincheng Miao, Luca Nils Philipp, Michael Wenzel, Ingo Fischer, Roland Mitric
Excimer formation dynamics in the isolated tetracene dimer
Chem. Sci., 2021, 12, 11965-11975
2. Marco Flock, Lea Bosse, Dustin Kaiser, Bernd Engels, Ingo Fischer
A time-resolved photoelectron imaging study on isolated tolane: observation of the biradicalic 1Au state
Phys. Chem. Chem. Phys., 2019, 21, 13157-13164
3. Anja Röder, Jens Petersen, Kevin Issler, Ingo Fischer, Roland Mitrić, Lionel Poisson
Exploring the Excited-State Dynamics of Hydrocarbon Radicals, Biradicals, and Carbenes Using Time-Resolved Photoelectron Spectroscopy and Field-Induced Surface Hopping Simulations
J. Phys. Chem. A 2019, 123, 10643−10662
4. Joscha Hoche, Hans-Christian Schmitt, Alexander Humeniuk, Ingo Fischer, Roland Mitrić, Merle I. S. Röhr
The mechanism of excimer formation: an experimental and theoretical study on the pyrene dimer
Phys. Chem. Chem. Phys., 2017, 19, 25002-25015