Xiao Li, Dongyu Zhang, Wenlian Li
Feb 26, 2008
Citations
0
Influential Citations
34
Citations
Journal
Applied Physics Letters
Abstract
A phosphorescent (Ph) cyclometallated rhenium (I) (ReI) complex was synthesized by reacting 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline with pentacarbonylbromorhenium in refluxing toluene solutions. The precipitates were easily sublimed to obtain a pure electrically neutral carbonyl diamine ReI complex, (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline)Re(CO)3Br. The Re complex was used as an orange emitting dopant in 4,4′-N,N′-dicarbazole-biphenyl host to fabricate Ph organic light-emitting diodes (PhOLEDs). The maximum electroluminescence (EL) efficiency and luminance of 21.8cd∕A and 8315cd∕cm2 were harvested, respectively, which were the highest EL results among the PhOLEDs based on ReI complexes. The improvements of the EL performances could be ascribed to the synergistic effects of together incorporation of two reciprocally repulsive phenyl and methyl groups on the backbone of 1,10-phenanthroline molecule of the ligand.