Highly efficient orange phosphorescent organic light-emitting diodes with (4-(3,5-dimethylphenyl)-2-(m-tolyl)pyridine)-based iridium complex

Abstract A new (4-(3,5-dimethylphenyl)-2-(m-tolyl)pyridine)-based iridium complex was synthesized for highly efficient orange phosphorescent organic light-emitting diodes (PhOLEDs). The effect of introduction of a methyl substituent into the 4-position of the phenyl ring in a phenylpyridine chelating ligand was studied. The PhOLEDs based on this newly-synthesized iridium complex exhibited maximum external quantum and current efficiencies of 20.33 % and 61.16 cd/A, respectively. These respective values maintained over 15% and 48 cd/A even at a very high luminance of 15000 cd/m2 with Commission Internationale de l'Eclairage coordinates of (0.49, 0.51).