Development of highly efficient circularly polarized organic light‐emitting diodes (CPOLEDs) has gained increasing interest as they show improved luminous efficiency and high contract 3D images in OLED displays. In this work, a series of binaphthalene‐containing luminogenic enantiomers with aggregation‐induced emission (AIE) and delayed fluorescence properties is designed and synthesized. These molecules can emit from green to red light depending on the solvent polarity due to the twisted intramolecular charge transfer effect. However, their solid powders show bright light emissions, demonstrating a phenomenon of AIE. All the molecules exhibit Cotton effects and circularly polarized luminescence in toluene solution and films. Multilayer CPOLEDs using the doped and neat films of the molecules as emitting layers are fabricated, which exhibit high external quantum efficiency of up to 9.3% and 3.5% and electroluminescence dissymmetry factor (gEL) of up to +0.026/−0.021 and +0.06/−0.06, respectively. Compared with doped CPOLEDs, the nondoped ones show higher gEL and much smaller current efficiency roll‐off due to the stronger AIE effect. By altering the donor unit, the electroluminescence maximum of the doped film can vary from 493 to 571 nm. As far as it is known, this is the first example of efficient CPOLEDs based on small chiral organic molecules.
Constructing
artificial helical structures through hierarchical
self-assembly and exploring the underlying mechanism are important,
and they help gain insight from the structures, processes, and functions
from the biological helices and facilitate the development of material
science and nanotechnology. Herein, the two enantiomers of chiral
Au(I) complexes (
S
)-1 and
(
R
)-1 were synthesized,
and they exhibited impressive spontaneous hierarchical self-assembly
transitions from vesicles to helical fibers. An impressive chirality
inversion and amplification was accompanied by the assembly transition,
as elucidated by the results of in situ and time-dependent
circular dichroism spectroscopy and scanning electron microscope imaging.
The two enantiomers could serve as ideal chiral templates to co-assemble
with other achiral luminogens to efficiently induce the resulting
co-assembly systems to show circularly polarized luminescence (CPL).
Our work has provided a simple but efficient way to explore the sophisticated
self-assembly process and presented a facile and effective strategy
to fabricate architectures with CPL properties.
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