Highly Efficient Cuprous Complexes with Thermally Activated Delayed Fluorescence for Solution-Processed Organic Light-Emitting Devices

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• 作者：Dong Liang ; Xu-Lin Chen ; Jian-Zhen Liao ; Jin-Yu Hu ; Ji-Hui Jia ; Can-Zhong Lu
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：August 1, 2016
• 年：2016
• 卷：55
• 期：15
• 页码：7467-7475
• 全文大小：534K
• 年卷期：0
• ISSN：1520-510X

文摘

Two mononuclear cuprous complexes [Cu(PNNA)(POP)]BF₄ (1) and [Cu(PNNA)(Xantphos)]BF₄ (2) (PNNA = 9,9-dimethyl-10-(6-(3-phenyl-1H-pyrazol-1-yl)pyridin-3-yl)-9,10-dihydroacridine, POP = bis[2-(dipenylphosphino)phenyl]ether, Xantphos =4,5-bis(diphenylphosphino)-9,9-dimethylxanthene), with intense bluish-green luminescence based on a new diimine ligand were designed and synthesized. Their structural, electrochemical, and photophysical properties were characterized by single-crystal X-ray analysis, cyclic voltammetry, temperature dependence of spectroscopy, time-dependent emission spectroscopy, etc. The complexes exhibit high photoluminescence quantum yields in doped films (up to 74.6%) at room temperature. Thermally activated delayed fluorescence based on intraligand charge transfer was observed by grafting a strong electron-donor moiety, 9,9-dimethylacridan, on the diimine ligand, which is supported by the density functional theory calculations on two complexes. Highly efficient solution-processed OLEDs based on these two complexes were fabricated, among which the electroluminescent device using 2 as dopant shows a peak external quantum efficiency of 7.42%, a peak current efficiency of 20.24 cd/A, and a maximum brightness of 5579 cd/m².