Regensburg 2016 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 30: Poster: Organic Electronics and Photovoltaics

CPP 30.31: Poster

Dienstag, 8. März 2016, 18:15–21:00, Poster B2

Thermally activated delayed fluorescence (TADF) in organic light emitting devices (OLEDs) utilizing carbazol-donor-benzofluoride-acceptor complexes — •Ludwig Popp¹, Reinhard Scholz¹, Paul Kleine¹, Ramunas Lygaitis^1,2, Florian Wüst¹, Eni Dodbiba¹, Simone Lenk¹, and Sebastian Reineke¹ — ¹Institut für Angewandte Photophysik, Technische Universität Dresden, Germany — ²Department of Organic Technology, Kaunas University of Technology, Lithuania

Thermally activated delayed fluorescence (TADF) takes place in fluorescent molecules where the energy splitting between the lowest excited singlet and triplet state (ST-splitting, Δ_ST) is about k_B T at room temperature. Due to the small ST-splitting, the excited triplet states are easily converted into fluorescent singlet states via reverse intersystem crossing (RISC). This excitonic scheme is favorable for OLEDs, because it allows for making use of the large fraction of non-radiative triplets, which are formed under electroluminescence operation.
In this study, a new series of carbazol-donor-benzofluoride-acceptor complexes ("xFyCz") is introduced where x denotes the number of fluorine atoms saturating the acceptor and y is the number of carbozol donor groups. Various investigations are shown such as absorbance and photoluminescence spectroscopy in solution and thin films, solvatochromism as well as the application and performance study of the emitters in actual OLEDs including e.g. j-V and luminance measurements, power efficiency and external quantum efficiency (EQE) up to 12 % for 1F4Cz.