AIE‐active Circularly Polarized Thermally Activated Delayed Fluorescence Emitters for Stable Solution‐Processed Circularly Polarized Electroluminescence

Circularly polarized organic light‐emitting diodes (CP‐OLEDs) have significant promise for naked‐eye 3D displays. However, most devices are fabricated using vacuum deposition technology, and development of efficient solution‐processed CP‐OLEDs, particularly those exhibiting low efficiency roll‐off, remains a formidable challenge. This research successfully designed and synthesized two pairs of thermally activated delayed fluorescence (TADF) enantiomers through isomer engineering, namely (R/S)‐N‐5‐TPA and (R/S)‐N‐4‐TPA, which features fifth and fourth substitution sites of phthalimide (acceptor) by tri‐phenylamine (donor), respectively. Both molecules displayed aggregation‐induced emission (AIE) properties. Notably, the CP‐OLED devices, fabricated by solution‐process, exhibited vivid blue‐green and green emission with the maximum current efficiency of 7.4 and 29.6 cd A‐1, the external quantum efficiency of 2.7% and 10.2%, and the low efficiency roll‐off of 3.7% and 16.7%. Moreover, these devices demonstrated CP‐EL signals with gEL values of +6.61 × 10‐4 /‐6.84 × 10‐4 and +1.13 × 10‐3/‐1.25 × 10‐3, respectively.