Narrowband Emissive TADF Conjugated Polymers towards Highly Efficient Solution‐Processible OLEDs

Abstract Thermally activated delayed fluorescence (TADF) conjugated polymers usually show broad emission spectra due to the large structure relaxation, which is not desirable for high‐quality organic light‐emitting diode (OLED) displays. Herein, through attaching multiple resonance (MR) induced emitting moiety as pendant onto the polycarbazole backbone, TADF conjugated polymers with narrowband emission are demonstrated. The obtained conjugated polymers exhibit typical TADF characteristics with narrowband emission with full‐width at half‐maximums (FWHMs) of 33–43 nm. The solution‐processed devices employing these polymers as emissive layers realize excellent performances with maximum external quantum efficiency (EQE) of 17.5 %, emission peak at 496 nm and FWHM of 34 nm.