This work is supported by National Natural Science Foundation of China (21788102), Natural Science Foundation of Guangdong Province (2022A1515010315)
Organic red luminogens are seriously bound by that of the energy gap law, giving rise to severe nonradiative decay of excited state and consequently low photoluminescence quantum yield (ΦPL). Herein, two red anthraquinone-based luminogens, AQ-2DPAC and AQ-2PDPAC, are synthesized by using different linking modes between the electron donor and the electron acceptor (D-A) with or without the phenyl ring as π-bridge. Their electronic structures, thermal properties, photophysical properties, and electroluminescent properties are investigated systematically to assess the impact of the phenyl bridge on their photoluminescence properties. Both highly twisted luminogens exhibit obvious aggregation-induced emission and delayed fluorescence features, and the elongation of D-A separation distance via the introduction of phenyl bridge can simultaneously decrease singlet-triplet energy splitting, enhance fluorescence decay rate and consequently increase ΦPL. Therefore, the ΦPL of D-π-A-type AQ-2PDPAC (52%) is much larger than that of D-A-type AQ-2DPAC (19%). The organic light-emitting diode employing AQ-2PDPAC as emitter realizes a high maximum external quantum efficiency of 13.7%, and a maxima luminance of 12 260 cd·m－2.
JIANG Ruming, LIU Hao, XU Jingwen, et al. Design, Synthesis and Optoelectronic Properties of Red Delayed Fluorescence Materials Based on Anthraquinone[J]. Journal of Integration Technology,2023,12(6):1-13Copy