摘要
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’-(9 H-carbazol-9-yl)-2,5-dimethyl-[1,1’-biphe nyl]-4-yl)anthracen-9-yl)benzonitrile(2 M-ph-pCzAnBzt)and 4-(10-(4-(9 H-carbazol-9-yl)-2,5-dimethyl phenyl)anthracen-9-yl)benzonitrile(2 M-pCzAnBzt).In particular,2 M-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.
有机电致发光器件(OLED)因其超轻薄和易于实现柔性等优点而成为全彩色显示领域的研究热点.开发高性能、低成本的深蓝光荧光发光材料对满足未来8K电视高品质显示的超高色域要求至关重要.在多环芳香烃中,蒽基团具备高荧光量子效率(PLQY)和良好的载流子传输能力,而被广泛应用于深蓝光发光材料的构建.本文基于蒽核心,利用外围配体基团调控分子构型,合成出了高性能发光材料2M-ph-pCzAnBzt和2M-pCzAnBzt.特别是采用2M-ph-pCzAnBzt所制备的非掺杂发光层结构的器件,外量子效率超过10%,色度坐标CIEy值<0.06,超过NTSC标准.本文创新性地提出高能反向系间窜越与三重态-三重态湮灭上转换协同作用机制,并结合量化计算分析、敏化实验研究和纳秒瞬态吸收光谱分析予以验证,为解决高效率深蓝光荧光OLED缺乏的瓶颈问题开辟了一条新的技术路线.
作者
Runda Guo
Wei Liu
Shian Ying
Yuwei Xu
Yating Wen
Yaxiong Wang
Dehua Hu
Xianfeng Qiao
Bing Yang
Dongge Ma
Lei Wang
郭闰达;刘威;应士安;徐玉伟;温雅婷;王亚雄;胡德华;乔现峰;杨兵;马东阁;王磊(Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China;State Key Laboratory of Luminescent Materials and Devices,Institute of Polymer Optoelectronic Materials and Devices,South China University of Technology,Guangzhou 510640,China;State Key Laboratory of Supramolecular Structure and Materials,Jilin University,Changchun 130012,China)
基金
supported by the National Natural Science Foundation of China(62004074,51727809)
the Science and Technology Department of Hubei Province(2019AAA063,2020BAA016)。
