Solution‐Processed,Undoped, Deep‐Blue Organic Light‐Emitting Diodes Based on Starburst Oligofluorenes with a Planar Triphenylamine Core |
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| Authors: | Cui Liu Yanhu Li Yingyue Zhang Prof Chuluo Yang Prof Hongbin Wu Prof Jingui Qin Prof Yong Cao |
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| Institution: | 1. Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072 (P.R. China), Fax: (+86)?27‐68756757;2. Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640 (P.R. China) |
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| Abstract: | A series of starburst oligomers (T1–T3) that contained a fully diarylmethene‐bridged triphenylamine core and oligofluorene arms were designed and synthesized through Suzuki cross‐coupling reactions. Their thermal, photophysical, and electrochemical properties were also investigated. These materials showed high glass transition, in the range of 123–129 °C, and good film‐forming abilities. They displayed deep‐blue emission both in solution and as thin films. Solution‐processed devices based on these oligomers exhibited highly efficient deep‐blue electroluminescence and the device performances were significantly enhanced with the extension of the oligofluorene arms. The double‐layered device that contained T3 as an emitter showed a maximum current efficiency of 3.83 cd A?1 and a maximum external quantum efficiency of 4.19 % with CIE coordinates of (0.16, 0.09), which are among the highest values for undoped deep‐blue OLEDs that are based on solution‐processable starburst oligomers. |
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| Keywords: | conjugation cross‐coupling fluorescence OLEDs oligomers |
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