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Science China Materials

, Volume 62, Issue 5, pp 719–728 | Cite as

Improving performance of thermally activated delayed fluorescence emitter by extending its LUMO distribution

  • Ke Ke (柯珂)
  • Jia-Xiong Chen (陈嘉雄)
  • Ming Zhang (张明)
  • Kai Wang (王凯)Email author
  • Yi-Zhong Shi (史益忠)
  • Hui Lin (林慧)
  • Cai-Jun Zheng (郑才俊)Email author
  • Si-Lu Tao (陶斯禄)
  • Xiao-Hong Zhang (张晓宏)Email author
Articles

Abstract

An optimized compound 9-(9,9-dimethylacridin-10(9H)-yl)-6H-benzo[c]ch-romen-6-one (MAB) was designed and synthesized based on our previously reported TADF emitter 6-(9,9-dimethylacridin-10(9H)-yl)-3-methyl-1H-isochromen-1-one (MAC) to further improve the performance of thermally activated delayed fluorescence (TADF) emitters. With the additional phenyl in coumarin-contained plane, MAB possesses an extended distribution of the lowest unoccupied molecular orbitals (LUMO), and thus realizes reduced electron exchange between the frontier molecular orbitals and a stretched molecular dipole moment compared with MAC. MAB based organic light-emitting diode (OLED) exhibits a remarkable maximum external quantum efficiency (EQE) of 21.7%, which is much better than the maximum EQE of MAC-based OLED with a value of 12.8%. Our work proves that extending the distribution of LUMO is a simple but effective method to improve the efficiency of TADF emitter.

Keywords

organic light-emitting diode thermally activated delayed fluorescence lumo distribution external quantum efficiency 

通过扩展LUMO分布提高热激活延迟荧光材料的性能

摘要

为了进一步提高热激活延迟荧光(TADF)发射体的性能, 我们基于之前报道的TADF材料MAC, 设计并合成了优化的化合物MAB. 通过在香豆素平面中加入苯基, 扩展了MAB的最低未占据分子轨道(LUMO)的分布. 与MAC相比, MAB减少了前沿分子轨道的电子交换并且延展了分子偶极矩, 从而提升了材料性能. 基于MAB的有机发光二极管(OLED)的最大外量子效率(EQE)为21.7%, 远远高于采用MAC作 为发光材料的OLED器件12.8%的最大EQE. 我们的工作证明, 扩展LUMO的分布是提高TADF材料性能的一种简单而有效的方法.

Notes

Acknowledgements

This work was supported by the National Natural Science Foundation of China (51773029, 51533005 and 51373190), the National Key Research & Development Program of China (2016YFB0401002), Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and the 111 Project and Qing Lan Project, China.

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Copyright information

© Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Ke Ke (柯珂)
    • 1
    • 2
  • Jia-Xiong Chen (陈嘉雄)
    • 2
  • Ming Zhang (张明)
    • 1
    • 2
  • Kai Wang (王凯)
    • 2
    Email author
  • Yi-Zhong Shi (史益忠)
    • 2
  • Hui Lin (林慧)
    • 1
  • Cai-Jun Zheng (郑才俊)
    • 1
    Email author
  • Si-Lu Tao (陶斯禄)
    • 1
  • Xiao-Hong Zhang (张晓宏)
    • 2
    Email author
  1. 1.School of Optoelectronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengduChina
  2. 2.Functional Nano and Soft Materials Laboratory (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and TechnologySoochow UniversitySuzhouChina

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