Yu Ling, Wu Zhongbin, Xie Guohua, Zeng Weixuan, Ma Dongge, Yang Chuluo
Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials , Hubei Key Lab on Organic and Polymeric Optoelectronic Materials , Department of Chemistry , Wuhan University , Wuhan , 430072 , People's Republic of China . Email:
State Key Laboratory of Polymer Physics and Chemistry , Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , People's Republic of China . Email:
Chem Sci. 2017 Dec 13;9(5):1385-1391. doi: 10.1039/c7sc04669c. eCollection 2018 Feb 7.
Simultaneously achieving high efficiency and low efficiency roll-off remains a big challenge for OLEDs based on thermally activated delayed fluorescence (TADF) emitters. To address this issue, we elaborately designed and synthesized a series of new emitters with both TADF and aggregation-induced emission (AIE) properties by introducing 9,9-dimethyl-9,10-dihydroacridine (DMAC) or 10-phenoxazine (PXZ) as donor units into a quinoxaline framework. By tuning the electron-donating capability of the donor as well as the amount of donor unit, the photophysical properties of the TADF-AIE emitters can be systematically regulated, with emissions ranging from green to red. We demonstrated efficient doped OLEDs with a maximum EQE of 22.4%, a maximum current efficiency (CE) of 80.3 cd A and a maximum power efficiency (PE) of 64.1 lm W for the green device, and an EQE of 14.1%, a CE of 36.1 cd A and a PE of 28.1 lm W for the orange device. Remarkably, these orange devices rendered small roll-offs of 1.4% and 21.3% respectively at a luminance of 100 and 1000 cd m. Attributed to the unique TADF and AIE features, the non-doped devices perform outstandingly with an EQE of 12.0%, a CE of 41.2 cd A and a PE of 45.4 lm W.
对于基于热激活延迟荧光（TADF）发光体的有机发光二极管（OLED）而言，同时实现高效率和低效率滚降仍然是一项巨大的挑战。为了解决这一问题，我们精心设计并合成了一系列兼具TADF和聚集诱导发光（AIE）特性的新型发光体，方法是将9,9-二甲基-9,10-二氢吖啶（DMAC）或10-吩恶嗪（PXZ）作为供体单元引入喹喔啉骨架中。通过调节供体的给电子能力以及供体单元的数量，可以系统地调控TADF-AIE发光体的光物理性质，其发射光范围从绿色到红色。我们展示了高效掺杂的OLED，绿色器件的最大外量子效率（EQE）为22.4%，最大电流效率（CE）为80.3 cd/A，最大功率效率（PE）为64.1 lm/W；橙色器件的EQE为14.1%，CE为36.1 cd/A，PE为28.1 lm/W。值得注意的是，这些橙色器件在100和1000 cd/m²的亮度下分别具有1.4%和21.3%的小滚降。由于独特的TADF和AIE特性，非掺杂器件表现出色，EQE为12.0%，CE为41.2 cd/A，PE为45.4 lm/W。
