It is well-known that high-performance circularly polarized organic light-emitting diodes (CP-OLEDs) remain a formidable challenge to the future application of circularly polarized luminescent (CPL)-active materials. Herein, the design of a pair of AIE-active chiral enantiomers (L/D-HP) is described to construct chiral co-assemblies with an achiral naphthalimide dye (NTi). The resulting co-assemblies emit an inverted CPL signal compared with that from the L/D-HP enantiomers. After thermal annealing at 120 °C, the inverted CPL signal of this kind of L/D-HP-NTi with a 1:1 molar ratio shows regular and ordered helical nanofibers arranged through intermolecularly ordered layered packing and is accompanied with a further amplified effect (|gem | = 0.032, λem = 535 nm). Significantly, non-doped CP-OLEDs based on a device emitting layer (EML) of L/D-HP-NTi exhibits a low turn-on voltage (Von ) of 4.7 V, a high maximum brightness (Lmax ) of 2001 cd m-2 , and moderate maximum external quantum efficiency (EQEmax ) of 2.3%, as well as excellent circularly polarized electroluminescence (CP-EL) (|gEL | = 0.023, λem = 533 nm).
Keywords: aggregation-induced emission; chiral amplification; chiral co-assembly; chiral inversion; circularly polarized electroluminescence.
© 2022 Wiley-VCH GmbH.