Comparative study on electroluminescence efficiencies and operational stability of blue TADF materials based on xanthone or triphenyltriazine acceptors

Abstract

The development of blue thermally activated delayed fluorescence (TADF) materials holds high importance for next-generation display and lighting technologies, yet their device stability remains a critical challenge for commercialization. In this work, we report two blue TADF materials incorporating the same stable pyridine-derived donor but different acceptors of xanthone (XT) and triphenyltriazine (TRZ), respectively. They exhibit excellent thermal stability and efficient blue TADF properties. When employed as emitters in organic light-emitting diodes (OLEDs), they show similar maximum external quantum efficiencies (EQE_maxs) of about 24%. However, the XT-based TADF emitter exhibits a longer operational lifetime than the TRZ-based emitter. What's more, when these two materials serve as sensitizers for a green multi-resonance TADF emitter, the XT-based sensitizer still provides a higher EQE_max and a longer operational lifetime than the TRZ-based sensitizer. These findings underscore the high potential of XT-based acceptors in the design of stable TADF emitters and sensitizers for fabricating high-performance OLEDs.