Constructing Efficient Narrow‐Spectrum Circularly Polarized Organic Light‐Emitting Diodes with Near‐Ultraviolet Chiral Assistant Dopants

ABSTRACT Ultraviolet (UV) and near‐ultraviolet (NUV) chiral materials are viable candidates as assistant dopants for constructing narrow‐spectrum circularly polarized organic light‐emitting diodes (CP‐OLEDs), which can be applied in next‐generation three‐dimensional displays. However, UV/NUV materials that fully satisfy the stringent requirements for chiral assistant dopants remain scarce. Herein, a pair of enantiomers, ( S )/( R )‐OBNPCN‐SFIAC, were designed, synthesized and characterized, which exhibit efficient NUV circularly polarized luminescence (CPL) with high‐level reverse intersystem crossing (hRISC) properties. They function efficiently as emitters in non‐doped and doped CP‐OLEDs, providing maximum external quantum efficiencies ( EQE max s) of 6.72% and 7.47%, respectively, along with absolute electroluminescence dissymmetry factors (| g EL |s) of up to 7.35 × 10 −3 . Also, they can serve as assistant dopants in narrow‐spectrum blue, green and orange multi‐resonance thermally activated delayed fluorescence (MR‐TADF) OLEDs, furnishing impressive EQE max s and | g EL |s of 38.65% and 8.67 × 10 −3 , respectively. To the best of our knowledge, the above results are amongst the best of the reported narrow‐spectrum CP‐OLEDs so far.