Regensburg 2022 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 12: Poster 1
CPP 12.56: Poster
Montag, 5. September 2022, 18:00–20:00, P1
Matrix Influence on the Photodynamics of a TADF-Emitting Molecule — •Björn Ewald1, Ulrich Mueller1, Jonas Gehrig1, Jonas Bellmann1, and Jens Pflaum1,2 — 1Experimental Physics VI, University of Würzburg, 97074 Würzburg — 2ZAE Bayern, 97074 Würzburg
The singlet-triplet dynamics of thermally activated delayed fluorescence (TADF) emitters is of high technological relevance for their application in 3rd generation Organic Light Emitting Diodes. In this respect, the molecular and solid-state properties of the matrix material hosting the molecular TADF-dopant, may drastically influence its confirmation, the related energetics and thus, its rate dynamics and the overall OLED efficiency. By virtue of their dark and long-living nature, spectroscopic access to the population dynamics of involved triplet states in such host-guest systems is not trivial. Here we applied a spectroscopic method, based on transient intensity-modulated photoluminescence (TIM-PL). Resting on a generic three level scheme, this technique yields access to the singlet-triplet population dynamics and the corresponding rates in TADF host-guest blends. We studied the photophysics of the TADF-emitter TXO-TPA doped into matrices with different crystalline order (PMMA and mCP). We can confirm that local matrix effects impose a significant impact on the rate dynamics and the singlet-triplet conversion. Particularly the intersystemcrossing rate can be drastically influenced by the local matrix environment. Hence the data obtained by the TIM-PL method, allow for a more rational selection of suited TADF guest-matrix combinations.