Bright red organic light-emitting diodes doped with a fluorescent dye

We have evaluated a synthetic red fluorescent dye, 6-methyl-3-[3-(1,1,6,6-tetramethyl-10-oxo-2,3,5,6-tetrahydro-1H,4H,10H-11-oxa-3a-aza-benzo[de]anthracen-9-yl)-acryloyl]-pyran-2,4-dione (AAAP), as a dopant for an organic light-emitting diode (LED). Bright emission of a good red (maximum luminance: 5600 cd/m(2), chromaticity coordinates: x=0.63, y=0.36) was obtained. The device consisted of ITO/TPD(50 nm)/Alq(3) doped with AAAP(1.5 mol %,15 nm)/bOXDF(20 nm)/Alq(3)(25 nm)/Mg:Ag (ITO: indium tin oxide, TPD: N, N'-diphenyl- N,N'-di(3- methylphenyl)-1,1'biphenyl-4,4'-diamine, Alq(3): tris (8-hydroxyquinolinato)-aluminum (III), bOXDF:2,2-bis[5-(4-biphenyl)-1,3,4-oxadiazole-2-yl-4,1 -phenylene]-hexafluoropropane). The bands of fluorescence of the Alq(3) host and of absorption of the AAAP dopant overlap in an advantageous way, and insertion of the bOXDF layer between the emission layer, doped with AAAP, and Alq(3) layer, made for a device with good properties. (C) 2000 American Institute of Physics. [S0003-6951(00)05746-6].