Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 50: Poster: Organic Electronics and Photovoltaics, Molecular Excitations
CPP 50.21: Poster
Mittwoch, 22. März 2017, 18:30–21:00, P3
Investigation of Spin States Involved in Thermally Activated Delayed Fluorescence by Magnetic Resonance Methods — •Benjamin Krugmann1, Nikolai Bunzmann1, Sebastian Weissenseel1, Jeannine Grüne1, Andreas Sperlich1, and Vladimir Dyakonov1,2 — 1Experimental Physics VI, Julius Maximilian University of Würzburg, 97074 Würzburg — 2Bayerisches Zentrum für Angewandte Energieforschung (ZAE Bayern), 97074 Würzburg
Organic light emitting diodes (OLEDs) based on thermally activated delayed flourescence (TADF) can exhibit a maximum internal quantum efficiency (IQE) of 100% instead of the 25% IQE that classical fluorescence emitters reach. The TADF mechanism is believed to include thermally induced reverse intersystem crossing (RISC) between slightly energetically split triplet and singlet states of exiplexes. Here, we present measurements based on bilayer 4,4’,4”-Tris[phenyl(m-tolyl)amino]triphenylamine:Tris(2,4,6-triMethyl-3-(pyridin-3-yl)phenyl)borane (m-MTDATA:3TPYMB) OLEDs. We are using the spin sensitive method of electroluminescence detected magnetic resonance (ELDMR), in which spin states are energetically separated by an external magnetic field. Additionally, we apply microwaves to excite transitions between triplet states at resonance, where the emission of electroluminescence is elevated. By investigation of the resonant peak at different parameters we can draw conclusions about the spin dependent mechanisms involved in the TADF process.