Four new bipolar Indolo[3, 2-b]carbazole derivatives for blue OLEDs. (March 2021)

• Record Type: Journal Article
• Authors: Yang, Hongyan; Li, Yanmei; Zhao, Yuling; Yu, Shupei; Ma, Hailin; Qian, Long; Wang, Ruidong; Yu, Tianzhi; Su, Wenming
• Is Part Of: Dyes and pigments. Volume 187(2021)
• Publication Date: 2021-03
• Subjects: Indolo[3, 2-b]carbazole (ICZ) -- Imidazole derivative -- Photoluminescence -- Electroluminescence; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2020.109096
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: Four new indolo [3, 2- b ]carbazole derivatives containing imidazole-derived moieties, 2, 8-bis(4-(9-(4-( tert -butyl)phenyl)-9 H -pyreno [4, 5- d ]imidazol-10-yl)phenyl)-5, 11-bis(2-ethylhexyl)-5, 11-dihydroindolo [3, 2- b ]carbazole (Py-ICZ-Py ), 2, 8-bis(4-(1-(4-( tert -butyl)phenyl)-1 H -phenanthro [9, 10- d ]imidazol-2-yl)phenyl)-5, 11-bis(2-ethylhexyl)-5, 11-dihydroindolo [3, 2- b ]carbazole (PI-ICZ-PI ), 5, 11-bis(2-ethylhexyl)-2, 8-bis(4-(1-phenyl-1 H -benzo [ d ]imidazol-2-yl)phenyl)-5, 11-dihydroindolo [3, 2- b ]carbazole (BI-ICZ-BI ) and 2, 8-bis(4-(1-(4-( tert -butyl)phenyl)-4, 5-diphenyl-1 H -imidazol-2-yl)phenyl)-5, 11-bis(2-ethylhexyl)-5, 11-dihydroindolo [3, 2- b ]carbazole (IM-ICZ-IM ), were successfully synthesized for highly efficient blue light-emitting devices. The thermal stabilities, photophysical and electrochemical properties of the hybrid compounds were investigated. These hybrid compounds exhibited strong blue emissions in solutions. Furthermore, the vacuum-processed doped devices based on these compounds were fabricated, in which the devices based on the compound PI-ICZ-PI exhibited the best electroluminescence performance with a maximum brightness of 3973 cd/m 2, a maximum current efficiency of 3.67 cd/A and a maximum external quantum efficiency (EQE) of 2.64%. Graphical abstract: Image 1 Highlights: Four indolo [3, 2- b ]carbazole derivatives containing imidazole-derived moieties were synthesized for OLEDs. These compounds exhibited blue emissions as well as good thermal stability ( T d > 460 °C). The devices based on PI-ICZ-PI showed the brightness of 3973 cd/m 2 and luminous efficiency of 3.67 cd/A, and EQE of 2.64%.