Synergistic Modulation of Excited State Ingredients and Chiroptical Activity for High‐Performance Pure‐Green Circularly Polarized Electroluminescence

Abstract The integration of chiral elements within a multiple resonance (MR) motif affords a prospective avenue to construct satisfying emitters tailored for state‐of‐the‐art circularly polarized organic light–emitting diodes (CP‐OLEDs). However, the concurrently realizing of both high luminescence efficiency and favorable dissymmetry factors (g_PL) still remains a formidable challenge, particularly when aligning with the requirement of high color purity. Herein, a dual‐pronged approach is proposed to reconcile such trade‐offs by directly fusing a secondary chiral donor onto the MR scaffold, thereby facilitating a hybrid short/long‐range charge‐transfer with fine‐tuned compositions. Theoretical calculations unveil the pronounced impact of the chiral donor on meticulously refining the characteristics of excited states, therefore yielding a considerable g_PL of 3.3 × 10⁻³, along with a high fluorescence quantum yield of 0.97, and a rapid reverse intersystem crossing rate of 3.06 × 10⁵ s⁻¹ in one embodiment. Leveraging these merits, electroluminescence devices incorporating them as chiral dopants exhibit exceptional performance, showcasing a peak external quantum efficiency of 36.6% and remarkable Commission Internationale de L'Eclairage coordinates of (0.19, 0.71), which represent one of the most notable achievements among pure‐green CP‐OLEDs.