Mechanistic models for phosphorescent organic crystals

In this PhD project, the student will explore a series of organic crystals displaying high-yield phosphorescence and investigate the photochemical deactivation mechanisms. An in-depth research of the crystal structures will inform about crystallisation patterns, size and shape of cavities and intermolecular interactions and correlate them with the photochemical mechanisms. Several mechanisms will be explored with a particular focus on the role of triplet states and electron transfer. Based on these results, structure property-relationships with implications for material design will be proposed. Because of the lack of computational methods to investigate excited state processes in molecular aggregates, this project will have a strong method development component aiming at creating new software, which will be used for the study of the model crystals. The proposed excited state mechanisms will be probed using advanced time-resolved laser-spectroscopic experiments. Based on our results, we will propose new design guidelines to minimise the deactivation through undesirable mechanisms and maximise phosphorescence in the solid-state.