Achieving high-efficiency deep blue emitter with CIE_y < 0.06 (CIE, Commission Internationale de L’Eclairage) and external quantum efficiency (EQE) >10% has been a long-standing challenge for traditional fluorescent materials in organic light-emitting diodes (OLEDs). Here, we report the rational design and synthesis of two new deep blue luminogens: 4-(10-(4′-(9H-carbazol-9-yl)-2,5-dimethyl-[1,1′-biphenyl]-4-yl)anthracen-9-yl)benzonitrile (2M-ph-pCzAnBzt) and 4-(10-(4-(9H-carbazol-9-yl)-2,5-dimethylphenyl)anthracen-9-yl)benzonitrile (2M-pCzAnBzt). In particular, 2M-ph-pCzAnBzt produces saturated deep blue emissions in a non-doped electroluminescent device with an exceptionally high EQE of 10.44% and CIE_x,y (0.151, 0.057). The unprecedented electroluminescent efficiency is attributed to the combined effects of higher-order reversed intersystem crossing and triplet-triplet up-conversion, which are supported by analysis of theoretical calculation, triplet sensitization experiments, as well as nanosecond transient absorption spectroscopy. This research offers a new approach to resolve the shortage of high efficiency deep blue fluorescent emitters.

_{实现 CIE y} < 0.06（CIE，Commission Internationale de L'Eclairage）和外量子效率（EQE）>10%的高效深蓝光发射体 一直是有机发光二极管中传统荧光材料面临的长期挑战（有机发光二极管）。在这里，我们报告了两种新的深蓝色发光剂的合理设计和合成：4-(10-(4'-(9 H -carbazol-9-yl)-2,5-dimethyl-[1,1'-biphenyl] -4-yl)anthracen-9-yl)benzonitrile ( 2M-ph- p CzAnBzt ) 和 4-(10-(4-(9 H -carbazol -9-yl)-2,5-dimethylphenyl)anthracen-9-基）苯甲腈（ 2M- p CzAnBzt）。特别是2M-ph- p CzAnBzt在非掺杂电致发光器件中产生饱和的深蓝色发射，具有 10.44% 的极高 EQE 和 CIE _x,y (0.151, 0.057)。前所未有的电致发光效率归因于高阶反向系统间交叉和三重态-三重态上转换的综合效应，理论计算分析、三重态敏化实验以及纳秒级瞬态吸收光谱都支持这一点。该研究为解决高效深蓝色荧光发射体短缺问题提供了新途径。