Chemical Physics Letters, Vol.372, No.3-4, 577-582, 2003
Light emitting devices from blended films of ruthenium(II)bis(2,2'-bipyridine) (4,7-dimethyl-1,10-phenanthroline) complex with poly(N-vinylcarbazole)
The light emitting devices using ruthenium(II)bis(2,2'-bipyridine)(4,7-dimethyl-1,10-phenanthroline) [Ru(bpy)(2) DIM](2+) complex as emitter have been fabricated in two structures: indium-tin-oxide glass (ITO)/poly(N-vinylcarbazole) (PVK):[Ru(bpy)(2)DIM](2+)/Al and ITO/PVK:[Ru(bpy)(2)DIM](2+)/2,9-dimethyl-4,7-diphenyl-1, 10-phenanthroline (BCP)/tris-(8-hydroxyquinoline) aluminum (Alq(3))/Al. In ITO/PVK:[Ru(bpy)(2)DIM](2+)/Al, the emitter concentration influences both the turn on voltage and the emission wavelength. At 6 wt% [Ru(bpy)(2)DIM](2+) concentration, the device has a turn on voltage of 16 V and the emission peak at 600 nm. At 36 wt% [Ru(bpy)(2)DIM](2+) concentration, the device turn on voltage can be reduced to 3 V, with the emission peak at 620 nm. ITO/PVK:[Ru(bpy)(2)DIM](2+) (36 wt%)/BCP/Alq(3))/Al obtains a quantum efficiency one order of magnitude higher than ITO/PVK:[Ru(bpy)(2)DIM](2+) (36 wt%)/Al. (C) 2003 Elsevier Science B.V. All rights reserved.