Developing organic deep-blue multiple-resonance (MR) emitters with narrow full widths at half maximum (FWHMs) is of great significance for improving the color purity of organic light-emitting diodes (OLEDs). Herein, two MR polycyclic aromatic hydrocarbons with three-indolo[3,2,1-jk]carbazole (ICz)-embedded fragments are designed and synthesized prolonging multiple-ICz strategy, accompanied by a deep-blue narrowband emission of 452 nm, a FWHM of 20 nm, and high photoluminescence quantum yield of 76%. Theoretical studies unveil that enlarging the atomically separated frontier molecular orbital distribution and extending the π-electron delocalization on the PAH skeleton are conducive to bathochromic-shift emission and simultaneously maintaining a small FWHM. In addition, the optimized blue OLEDs fabricated with the nitrogen-embedded MR emitter achieved a high external quantum efficiency of 12.6%.

中文翻译：

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吲哚并咔唑基深蓝色多共振窄带发射体及高效有机发光二极管

开发窄半峰全宽（FWHM）的有机深蓝色多谐振（MR）发射器对于提高有机发光二极管（OLED）的色纯度具有重要意义。在此，设计并合成了两种具有三吲哚[3,2,1-jk]咔唑（ICz）嵌入片段的MR多环芳烃，延长了多ICz策略，并伴随着452 nm的深蓝色窄带发射，半高宽为20 nm，光致发光量子产率为76%。理论研究表明，扩大原子分离的前沿分子轨道分布和延长PAH骨架上的π电子离域有利于红移发射，同时保持较小的半高宽。此外，采用氮嵌入MR发射器制造的优化蓝色OLED实现了12.6%的高外量子效率。