级联敏化三元旋涂型磷光器件电致发光性能  

Electroluminescent Performances of Solution-processed Phosphorescent Organic Light-emitting Diodes Based on Cascade Energy Transfer of Ternary Blends

作　　者：高羽晗 谢国华[1,2,3] GAO Yuhan;XIE Guohua(College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China;Wuhan National Laboratory for Optoelectronics,Wuhan 430074,China;Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province,Shantou University,Shantou 515063,China)

机构地区：[1]武汉大学化学与分子科学学院,湖北武汉430072 [2]武汉光电国家研究中心,湖北武汉430074 [3]汕头大学化学系和广东省有序结构材料的制备与应用重点实验室,广东汕头515063

出　　处：《发光学报》2023年第2期219-226,共8页Chinese Journal of Luminescence

基　　金：国家自然科学基金(51873159,62175189);武汉光电国家研究中心开放基金(No.2019WNLOKF015);广东省有序结构材料的制备与应用重点实验室开放课题(No.KLPAOSM202003)。

摘　　要：金属配合物磷光分子在高浓度下易产生发光猝灭,通常采用主客体两元掺杂结构来提高电致发光效率。热激活延迟荧光(TADF)材料通过三线态激子的反向系间窜越理论上可达到100%的内量子效率。为探究不同主体材料在三元敏化磷光体系中的作用,本文基于TADF聚合物作为敏化剂、黄橙光磷光配合物作为发光材料,分别研究了以传统荧光材料和蓝色TADF主体构建的三元敏化的旋涂型有机电致发光器件性能。研究表明,在客体浓度分别为1%、5%、50%时,基于TADF主体的器件电致发光性能均优于相同浓度下以传统荧光主体构建的器件性能。其中当磷光配合物PO-01-TB掺杂浓度为1%时,以天蓝光TADF材料为主体制备的器件最大外量子效率为12.2%,相较于以传统荧光为主体的器件外量子效率(10.7%)提高了14%。这源于本身具有双极传输特性的TADF主体通过反向系间窜越通道增强了对敏化剂和客体的级联能量传递作用,减少了三线态激子的浓度猝灭和湮灭过程,提高了大电流注入下的激子利用率。Phosphorescent metal complexes tend to be quenched at high concentration.The host-guest strategy is usually employed to improve the electroluminescent efficiency.Due to the reverse intersystem crossing,thermally activated delayed fluorescence(TADF)materials could potentially achieve 100%internal quantum efficiency.To explore the influence of the host on the electroluminescence of the solution-processed organic light-emitting devices,the ternary-blend emitting layers were constructed with a TADF polymer as the sensitizer and a phosphorescent emitter which were hosted by a conventional fluorescent material and a TADF material,respectively.For the phosphorescent emitter with the concentration of 1%,5%and 50%,the external quantum efficiencies of the devices based on the sky-blue TADF host were respectively higher than those of the devices based on the conventional fluorescent host.With 1%phosphorescent emitter PO-01-TB doped in the ternary-blend emitting layer,the peak external quantum efficiency of the solution-processed device hosted by the TADF material DMAC-DPS was up to 12.2%,which was 14%higher than that of the device with the fluorescent host(10.7%).This is attributed to efficient cascade energy transfer in the presence of the TADF host with the bipolar property and reverse intersystem crossing,which alleviates the triplet annihilation and quenching effects under high driving current.

关 键 词：有机电致发光器件 三元敏化 热激活延迟荧光 磷光 能量传递 

分 类 号：TN383[电子电信—物理电子学]