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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 25: Hybrid, Organic and Perovskite Optoelectronics and Photovoltaics II
CPP 25.2: Vortrag
Dienstag, 10. März 2026, 11:45–12:00, ZEU/0260
Temperature-Dependent Spin-Sensitive Spectroscopy of Triplet-Exciton Dynamics in TADF OLEDs — •Ahmed Mohamed, Andreas Kohrmann, Vladimir Dyakonov, and Andreas Sperlich — Experimental Physics 6, University of Würzburg, 97074 Würzburg, Germany
Thermally Activated Delayed Fluorescence (TADF) enables efficient harvesting of triplet excitons through reverse intersystem crossing (rISC) in OLEDs. Previous studies have shown that TADF device operation is dominated by triplet excitons, whose densities exceed singlet and charge carrier densities by several orders of magnitude. A major limitation to TADF efficiency is the non-radiative loss of triplet excitons. Here, we analyze the transient photoluminescence (trPL) and transient electroluminescence (trEL) decays of the blue TADF emitter ν-DABNA hosted in TDBA-Si or mCP. Temperature-dependent trPL/trEL kinetics were modeled using a rate-equation framework. Key triplet-exciton parameters, including the lifetime, diffusion coefficient, diffusion length, and activation energies were extracted by considering both 1st and 2nd order triplet-exciton decay pathways. The spin properties of the triplet exciton were additionally identified using photoluminescence-detected magnetic resonance (PLDMR) measurements on the organic layer stack. Together, kinetic and spin analysis of triplet excitons provide a comprehensive picture of non-radiative quenching to guide future improvements of TADF OLEDs
Keywords: OLED; TADF; Triplet Excitons; TTA; PLDMR