Organic light-emitting devices using ruthenium (II) (4,7-diphenyl-1,10-phenanthroline)3 as dopant

The light emitting devices using ruthenium(II)(4,7-diphenyl-1,10-phenanthroline)3 ([Ru(dphphen)3]2+) complex as dopant and emitter in poly(N-vinylcarbazole) (PVK)-based blend matrix have been studied in different structures. In comparison with the indium-tin-oxide glass (ITO)/PVK:2-(4-biphenyl)-5-(4-ter-butylphenyl)-1,3,4-oxadiazole (PBD):[Ru(dphphen)3]2+/tris-(8-hydroxyquinoline) aluminum (Alq3)Al,ITO/PVK:PBD:[Ru(dphphen)3]2+/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/Alq3/LiF/Al, and ITO/PVK:N,N′-diphenyl-N,N′ -bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine (TPD):PBD:[Ru(dphphen)3]2+/BCP/Alq3/LiF/Al devices, the ITO/PVK:PBD:[Ru(dphphen)3]2+/Alq3/BCP/Alq3/LiF/Al device shows efficient improvement in device brightness and efficiency. Furthermore, the chromacity-tunable electroluminescence is obtained by the hybrid emission from [Ru(dphphen)3]2+ and Alq3 species in such a device structure.