Narrow‐Band Emission of Asymmetric 1,3‐Substituted Pyrene‐Based Deep‐Blue Emitters and Application in OLEDs

Abstract High‐efficiency organic blue light‐emitting materials with narrow‐band emission are fundamental components for constructing high color purity and high resolution in high‐performance organic light‐emitting diode (OLED) devices. Herein, new pyrene‐based blue emitters (8–10) with narrow‐band emission are synthesized by asymmetrically introducing biphenyl and triphenylamine units at the 1‐ and 3‐positions of pyrene, respectively. Due to the steric effect and through‐space conjugation, the synergistic effects of both groups not only boost these emitters 8–10 (CIE_y < 0.11) with aggregation‐induced emission (AIE) characteristics and high fluorescence quantum yield (>0.68), but also endow narrow full width at half maxima (FWHM) emission (≤36 nm) in the crystallized state (FWHM ≤ 55 nm in the film state). The EL spectra of pyrene‐based 8–10 in nondoped OLEDs exhibit blue emission with a maximum emission (λ_{max em}) in the range of 448–453 nm (CIE_y ≤ 0.12). The compounds 8–10 in doped‐OLEDs show a blue emission with a λ_{max em} in the range of 443–445 nm and CIE_y ≤ 0.08, with FWHM emission of 57–61 nm. The compound 10‐based doped OLED displays an impressive EL performance with a maximum brightness of 9756 cd m⁻² and a maximum external quantum efficiency of 2.58%.