Design Strategy of Blue and Yellow Thermally Activated Delayed Fluorescence Emitters and Their All-Fluorescence White OLEDs with External Quantum Efficiency beyond 20%
作者:Yunchuan Li、Xiang-Long Li、Dongjun Chen、Xinyi Cai、Gaozhan Xie、Zuozheng He、Yuan-Chun Wu、Alan Lien、Yong Cao、Shi-Jian Su
DOI:10.1002/adfm.201602507
日期:2016.10
Two thioxanthone‐derived isomeric series of thermally activated delayed fluorescence (TADF) emitters 1,6‐2TPA‐TX/3,6‐2TPA‐TX and 1,6‐2TPA‐TXO/3,6‐2TPA‐TXO are developed for organic light‐emitting diodes (OLEDs). Blue emission devices based on symmetrical 3,6‐2TPA‐TX with common vertical transition route realize an extremely high external quantum efficiency (EQE) of 23.7%, and an ever highest EQE of
开发了两个噻吨酮衍生的热激活延迟荧光(TADF)发射体异构体系列1,6‐2TPA‐TX / 3,6‐2TPA‐TX和1,6‐2TPA‐TXO / 3,6‐2TPA‐TXO发光二极管(OLED)。基于对称3,6-2TPA-TX且具有常见垂直过渡路径的蓝色发射器件实现了23.7%的极高外部量子效率(EQE),而基于3,6-2TPA-TX的黄色发射器件实现了24.3%的最高EQE,通过单独更改噻吨酮核心的硫原子价态来实现6-2TPA-TXO。相反,它们相应的不对称异构体受分子内能量转移的影响,而受非辐射失活途径的影响更大,从而给出低得多的EQE值(<5%)。通过将3,6‐2TPA‐TX用作蓝色发射器并将3,6‐2TPA‐TXO用作黄色发射器,EQE最高达到20。