9-Silafluorene and 9-germafluorene: novel platforms for highly efficient red phosphorescent organic light-emitting diodes. Issue 30 (20th July 2018)

• Record Type: Journal Article
• Authors: Liu, Xiang-Yang; Tian, Qi-Sheng; Zhao, Danli; Ran, Quan; Liao, Liang-Sheng; Fan, Jian
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 30(2018)
• Page Start: 8144
• Page End: 8151
• Publication Date: 2018-07-20
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8tc02851f
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : De novo molecular platforms have been applied to build host materials for highly efficient PHOLEDs. A 9-silafluorene derivative was studied for the first time as a host and an external quantum efficiency of over 28% was achieved successfully in red PHOLEDs. Abstract : Two novel heterofluorene motifs consisting of the group 14 elements Si and Ge were developed as robust molecular platforms for the construction of organic light-emitting diode (OLED) materials. These two compounds exhibited similar photophysical properties, thermal stabilities and electrochemical behaviors except for the charge transport abilities. The red OLED hosted by a 9-silafluorene derivative (DPS) with Ir(MDQ)2 (acac) as the emitter exhibited state-of-the-art current efficiency, power efficiency, and external quantum efficiency (EQE) with maxima of 50.7 cd A −1, 44.7 lm W −1, and 28.3%, respectively. In addition, the maximum EQE of a 9-germafluorene derivative (DPG)-based red device could reach 20%. These results indicated the great potential of group 14 element derivatives in the construction of highly efficient OLED materials.