A methyl-shield strategy enables efficient blue thermally activated delayed fluorescence hosts for high-performance fluorescent OLEDs
You Ran, Ge Yang, Yang Liu, Weiguo Han, Ge Gao, Rongchuan Su, Zhengyang Bin, Jingsong You
Abstract
Here, we report a novel methyl-shield strategy to design ideal TADF hosts for the improvement of the performance of TSF-OLEDs. The methyl group on the xanthone acceptor acts like a shield to protect the luminance center from close intermolecular hydrogen bonding with adjacent molecules, thus alleviating exciton quenching, and meanwhile the small size of the methyl group almost does not disturb the π-π stacking between acceptors, thus maintaining fast electron-transport pathways. dMeACRXTO having two methyl shields is exploited as the host to achieve a record-high EQE of 32.3%, which represents the first report of an EQE above 30% in TSF-OLEDs.
Topics & Concepts
FluorescenceStackingOLEDMaterials scienceQuenching (fluorescence)Intermolecular forcePhotochemistryAcceptorOptoelectronicsMethyl groupMoleculeChemistryNanotechnologyGroup (periodic table)OpticsPhysicsLayer (electronics)Organic chemistryCondensed matter physicsOrganic Light-Emitting Diodes ResearchOrganic Electronics and PhotovoltaicsGreen IT and Sustainability