题目：

Coumarin-Based Thermally Activated Delayed Fluorescence Emitters with High External Quantum Efficiency and Low Efficiency Roll-off in the Devices

作者：

Jia-Xiong Chen,^†Wei Liu,^‡,§ Cai-Jun Zheng,^*,‡,∥ Kai Wang,^†,‡ Ke Liang,^† Yi-Zhong Shi,^† Xue-Mei Ou,^*,† and Xiao-Hong Zhang^*,†

单位：

^†Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials, Soochow

University, Suzhou, Jiangsu 215123, P. R. China

^∥School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China

^‡Nano-organic Photoelectronic Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials,

Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China

^§College of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China

摘要：

Thermally activated delayed fluorescence (TADF) emittershave attracted much interest for their great applications in organic light-emitting diodes (OLEDs), but the TADF OLEDs are limited by largeefficiency roll-offs. In this study, we report two coumarin-based TADFemitters, 3-methyl-6-(10H-phenoxazin-10-yl)-1H-isochromen-1 �one(PHzMCO) and 9-(10H-phenoxazin-10-yl)-6H-benzo[c]chromen-6 �on(PHzBCO), with relatively high photoluminescence quantum yields(PLQYs) and extremely small singlet-triplet splittings. OLEDs using thesetwo TADF compounds as the emitters respectively demonstrate high externalquantum efficiencies of 17.8% for PHzMCO and 19.6% for PHzBCO, whichare the highest among the reported coumarin-derivative-based OLEDs. Moreimportantly, these devices based on PHzMCO and PHzBCO remained 10.3%and 12.9% at 10000 cd m^-2, respectively, showing relatively low efficiency roll-offs at high brightness. These results reveal that the TADF emitters with highPLQYs can effectively reduce the efficiency roll-off in the devices.

影响因子：

7.145

分区情况：

一区

链接：

http://pubs.acs.org/doi/abs/10.1021/acsami.6b15816

责任编辑：向丹婷  联系方式：dtxiang@suda.edu.cn