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

Abstract

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 Å copper phthalocyanine hole injection layer/500 Å N, N′-bis-(1- naphthy)-N, N′diphenyl-1,1′-biphenyl-4-4 ′-diamine hole transport layer/110 Å 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) (Alq3) doped with (0.1%) coumarin 6 emitting layer/200 Å Alq3 electron transport layer/5 Å 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/m2. The device turned on at 2.5 V. Its luminance was 8800 cd/m2 at 9 V, and the maximum efficiency was 5 lm/W. © 2002 American Institute of Physics.