B,N‐Embedded Hetero[9]helicene Toward Highly Efficient Circularly Polarized Electroluminescence

The intrinsic helical π-conjugated skeleton makes helicenes highly promising for circularly polarized electroluminescence (CPEL). Generally, carbon helicenes undergo low external quantum efficiency (EQE), while the incorporation of a multi-resonance thermally activated delayed fluorescence (MR-TADF) BN structure has led to an improvement. However, the reported B,N-embedded helicenes all show low electroluminescence dissymmetry factors (g