Regensburg 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 29: Poster II
HL 29.87: Poster
Dienstag, 18. März 2025, 18:00–20:00, P1
Structural Dynamics of Excimer Formation in single crystalline α-Perylene — •Helena Hollstein1, Simon Versmissen2, Bram Spijkerman2, Heinrich Schwoerer2, and Sebastian Hammer1 — 1University of Würzburg, 97074 Würzburg, Germany — 2Max-Planck-Institut für Struktur und Dynamik der Materie, 22761 Hamburg, Germany
In the field of organic semiconductors an exact understanding of the formation of multi-molecular excited states, such as excimers, and geometric inter-molecular changes caused thereby, is crucial but challenging. Quantum chemical methods are in principle able to capture all structural changes during excimer formation but are hardly feasible due to the complexity of organic crystals. Experimentally on the other hand, the molecular motion can be detected by ultra-fast electron diffraction (UED) on a femtosecond timescale [1], and by using structural modeling the molecular movement can be reconstructed from changes in the diffraction pattern [2].
In this contribution we examine the structural reorganization during the formation of the low lying excimer state in single crystalline perylene in its crystallographic α-phase by means of UED. We are able to reveal the pathways of the geometric relaxation during the excimer formation on a fs timescale and find that the formation happens on a 5 ps timescale.
Keywords: structural dynamics; ultra-fast electron diffraction; perylene