P‐109: C/N Fusion Controlled Emission Strategy for Narrow‐Emitting High‐Efficiency Organic Light‐Emitting Diodes

Two narrow emitting emitters were developed via a carbon/nitrogen (C/N) fusion strategy. The fusion‐induced rigid structures induced an MR effect similar to the boron frameworks. Both compounds offer narrow emission, very small Stocks shift, and high photoluminescence quantum yield. The fluorescence devices fabricated using m‐FLDID offer maximum efficiency (EQEmax) of above 5%, pure violet emission at 407 nm, and FWHM of 17 nm. Whereas the p‐ FLDID‐based thermally activated delayed fluorescence (TADF) devices showed EQEmax of above 25%, deep‐blue emission at 452 nm, and FWHM of 23 nm.