Efficient red organic light-emitting devices based on a europium complex

摘要

An efficient organic light-emitting device using a trivalent europium (Eu) complex Eu(Tmphen)(TTA)_(3) (TTA=thenoyltrifluoroacetone, Tmphen=3,4,7,8-tetramethyl-1,10-phenanthroline) as the dopant emitter was fabricated. The devices were a multilayer structure of indium tin oxide/N,N-diphenyl-N,N-bis(3-methylphenyl)-1,1-biphenyl-4,4-diamine (40 nm)/Eu complex:4,4-N,N-dicarbazole-biphenyl (1, 30 nm)/2,9-dimethyl,4,7-diphenyl-1,10-phenanthroline (20 nm)/AlQ (30 nm)/LiF (1 nm)/Al (100 nm). A pure red light with a peak of 612 nm and a half bandwidth of 3 nm, which is the characteristic emission of trivalent europium ion, was observed. The devices show the maximum luminance up to 800 cd/m~(2), an external quantum efficiency of 4.3, current efficiency of 4.7 cd/A, and power efficiency of 1.6 1m/W. At the brightness of 100 cd/m~(2), the quantum efficiency reaches 2.2 (2.3 cd/A).