Novel spirofluorene/indole/carbazole-based hole transport materials with high triplet energy for efficient green phosphorescent organic light-emitting diodes

摘要

Three novel host materials 9-(4-(5-(4-(9-phenyl-9H-fluoren-9-yl)phenyl)-1H-indol-1-yl)phenyl)-9H-carbazole (C1), 9-(4-(9,9-diphenyl-9H-fluoren-4-yl)-1H-indol-1-yl)-9-phenyl-9H-carbazole (c2) and 9(4-(5-(9,9-diphenyl-9H-fluoren-2-yl)-1H-indol-1-yl)phenyl)-9H-carbazole (C3) based on spirofluorene, indole and carbazole derivatives have been designed and synthesized. Their thermal, photophysical and electrochemical properties were fully investigated. The OLED devices with Cl C3 as host were fabricated to investigate their electroluminescent properties. Compound C3 obtained the best device performances with the maximum current efficiency of 45.2 cd A(-1) and the maximum power efficiency of 23.2 lm W-1 for green phosphorescent organic light-emitting diodes.