High-efficiency white organic light-emitting devices with dual doped structure

A dual doped structure was proposed for obtaining organic light-emitting devices with high-efficiency and full-spectrum white light emission. The device structure included indium tin oxide glass substrate/120 Angstrom copper phthalocyanine hole injection layer/500 Angstrom N, N'-bis-(1-naphthy)-N, N'diphenyl-1,1'-biphenyl-4-4'-diamine hole transport layer/110 Angstrom 1,4-bis(2,2-diphenylvinyl) biphenyl doped with 0.025% 4-Dicyanomethylene-2-methyl-6- [2-(2,3,6,7-tetra-hydro-1H,5Hbenzo[ij]quinolizin-8-yl)vinyl]-4H-pyran+tris- (8-hydroxyquinoline) (Alq(3)) doped with (0.1%) coumarin 6 emitting layer/200 Angstrom Alq(3) electron transport layer/5 Angstrom lithium fluoride (LiF)/aluminum (Al). A stable white emission [Commission Internationale de l'Eclairage 1931 chromaticity coordinate (X=0.30, Y=0.36)] was obtained for luminance ranging from 100 to 1000 cd/m(2). The device turned on at 2.5 V. Its luminance was 8800 cd/m(2) at 9 V, and the maximum efficiency was 5 lm/W. (C) 2002 American Institute of Physics.