Dyes and Pigments ( IF 4.5 ) Pub Date : 2020-11-06 , DOI: 10.1016/j.dyepig.2020.108981 Jiangnan Zhu , Wenxuan Song , Tianmei Zhang , Qingchen Dong , Jinhai Huang , Haitao Zhou , Jianhua Su
In this research, a novel macrocycle containing tetrabenzeneaza has been developed as a novel building block for hole transport materials (HTMs). Benefiting from its unique highly twisted spatial configuration, this macrocycle exhibits high triplet energy level (ET) as well as high hole mobility. Based on this aza macrocycle, two hole transporting materials, namely 2TPATPCA and 2CzTPCA, were designed and synthesized. Both 2TPATPCA and 2CzTPCA possess enough ETs, appropriate frontier orbital energy levels as well as good thermal stability, which promote them as universal HTMs in multicolor phosphorescent organic light-emitting devices (PhOLEDs) and thermal activated delay fluorescence (TADF) OLEDs. High external quantum efficiencies (EQEs) were realized in OLEDs using the these two HTMs. For example, sky bule PhOLED with 2CzTPCA showed a significantly improved maximum EQE of 20.3 % compared to that of the reference device using N,N'-Bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine (NPB) (EQE of 14.2 %) and 4,4'-Cyclohexylidenebis[N,N- bis(4-methyl phenyl)aniline (TAPC) (EQE of 12.2 %). Green TADF OLED using 2CzTPCA as HTM also exhibit a much improved maximum EQE of 17.9 % compared to that of the reference device based on NPB (EQE of 10.3 %). These results indicate this tetrabenzeneaza macrocyclic is a promising building block for developing universal high-performance HTMs.
中文翻译:
四苯氮杂大环:通用高性能空穴传输材料的新型平台
在这项研究中,已开发出一种含有四苯氮杂的新型大环化合物作为空穴传输材料(HTM)的新型构件。得益于其独特的高度扭曲的空间构型,该大环具有高三重态能级(E T)和高空穴迁移率。基于这个氮杂大环,设计并合成了两种空穴传输材料,即2TPATPCA和2CzTPCA。无论2TPATPCA和2CzTPCA具备足够的èTs,适当的前沿轨道能级以及良好的热稳定性,使其在多色磷光有机发光器件(PhOLED)和热激活延迟荧光(TADF)OLED中成为通用HTM。使用这两个HTM在OLED中实现了很高的外部量子效率(EQE)。例如,天空BULE与PHOLED 2CzTPCA表明相比于使用参考装置的的20.3%提高显著最大EQE N,N'-双(萘-1-基)-N,N'-双(苯基)联苯胺(NPB)(EQE为14.2%)和4,4'-环己叉基双[N,N-双(4-甲基苯基)苯胺(TAPC)(EQE为12.2%)。使用2CzTPCA的绿色TADF OLED因为与基于NPB的参考设备相比,HTM的最大EQE也提高了17.9%,EQE为10.3%。这些结果表明,这种四苯氮杂大环化合物是开发通用高性能HTM的有希望的基础。