Non-doped and doped circularly polarized organic light-emitting diodes with high performances based on chiral octahydro-binaphthyl delayed fluorescence luminophores
Circularly polarized organic light-emitting diodes (CP-OLEDs) are of great value for facilitating the development of the next generation of display technologies, especially for implementing real 3D display. 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 chiral source and 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 (|gPL|) around 2.0×10-3 in the toluene solution and neat/doped films. The non-doped and doped CP-OLEDs achieve markedly circularly polarized electroluminescence signals with |gEL| up to 2.9×10-3, high brightness over 25000 cd cm-2, high efficiency with maximum external quantum efficiency (EQEmax) of 12.4%, and negligible efficiency roll-off with EQE of 11.5% at the practical luminance of 1000 cd m-2, which are the best performances among the reported CP-devices to date.