Inverted and Amplified CP‐EL Behavior Promoted by AIE‐Active Chiral Co‐Assembled Helical Nanofibers

Abstract 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 (| g em | = 0.032, λ em = 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 ( V on ) of 4.7 V, a high maximum brightness ( L max ) of 2001 cd m −2 , and moderate maximum external quantum efficiency ( EQE max ) of 2.3%, as well as excellent circularly polarized electroluminescence (CP‐EL) (| g EL | = 0.023, λ em = 533 nm).