A blue thermally activated delayed fluorescence emitter developed by appending a fluorene moiety to a carbazole donor with meta-linkage for high-efficiency OLEDs. (22nd February 2018)

• Record Type: Journal Article
• Authors: Liang, Jiao-Jiao; Li, Yun; Yuan, Yi; Li, Si-Hua; Zhu, Xiang-Dong; Barlow, Stephen; Fung, Man-Keung; Jiang, Zuo-Quan; Marder, Seth R.; Liao, Liang-Sheng
• Is Part Of: Materials chemistry frontiers. Volume 2:Number 5(2018)
• Page Start: 917
• Page End: 922
• Publication Date: 2018-02-22
• Subjects: Materials science -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1039/c7qm00605e
• Languages: English
• ISSNs: 2052-1529

Abstract

Abstract : A new TADF emitter was developed for blue OLEDs, and its thermal, photophysical and electrochemical properties were investigated. Abstract : A new thermally activated delayed fluorescence (TADF) emitter, 3-(9, 9′-spirobi[fluoren]-6-yl)-9-(4-(4, 6-diphenyl-1, 3, 5-triazin-2-yl)phenyl)-9 H -carbazole (SFCC ), was developed for blue organic light-emitting diodes (OLEDs), and its thermal, photophysical and electrochemical properties were systematically investigated. Upon introducing a 9, 9′-spiro-bifluorene group through its C3 position to the C3 position of carbazole, the resulting new backbone had a more delocalized highest occupied molecular orbital (HOMO) than carbazole itself which led to a higher photoluminescence quantum yield (PLQY) compared with that of the control material, 3-bromo-9-(4-(4, 6-diphenyl-1, 3, 5-triazin-2-yl)phenyl)-9 H -carbazole (TRTZ ). The OLED based onSFCC as the blue TADF emitter has a maximum external quantum efficiency (EQE) of 10.59%, with Commission Internationale de L'Eclairage (CIE) coordinates of (0.17, 0.21), significantly surpassing the performance of the reference emitterTRTZ, indicating that the introduction of the 9, 9′-spiro-bifluorene unit is a promising strategy for the modification of TADF materials.