Non-doped and doped circularly polarized organic light-emitting diodes with high performances based on chiral octahydro-binaphthyl delayed fluorescent luminophores

摘要

Circularly polarized organic light-emitting diodes (CP-OLEDs) are of great value for facilitating the development of next generation display technologies, especially for implementing real 3D displays. However, most CP-OLEDs have insufficient efficiency and serious efficiency roll-off. In this study, a pair of octahydro-binaphthyl (OBN)-based chiral emitting enantiomers, (R/S)-OBN-DPA, were synthesized by ingeniously merging the chiral source and the luminophore skeleton of cyan and diphenylamine groups. The chirality-acceptor-donor (C-A-D) type enantiomers concurrently demonstrate a high photoluminescence quantum yield of 84.67%, and intense circularly polarized photoluminescence with dissymmetry factors (|g(PL)|) around 2.0 x 10(-3) in the films. The non-doped and doped CP-OLEDs achieve markedly circularly polarized electroluminescence signals with |g(EL)| up to 2.9 x 10(-3), high brightness over 25 000 cd cm(-2), high efficiency with a maximum external quantum efficiency (EQE(max)) of 12.4%, and negligible efficiency roll-off with an EQE of 11.5% at a practical luminance of 1000 cd m(-2), which are the best results among the reported CP-devices to date.