We have evaluated a synthetic red fluorescent dye, 6-methyl-3-[3-(1,1,6,6-tetramethyl-10-oxo2,3,5,6-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/m2, chromaticity coordinates: x=0.63, y=0.36) was obtained. The device consisted of ITO/TPD(50 nm)/Alq3 doped with AAAP(1.5 mol %,15 nm)/bOXDF(20 nm)/Alq3(25 nm)/Mg:Ag (ITO: indium tin oxide, TPD: N, N′-diphenyl- N,N′-di(3-methylphenyl)-1, 1′biphenyl-4,4′-diamine, Alq3: 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 Alq3 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 Alq3 layer, made for a device with good properties.

New fluorescence blue host (BH) materials for achieving low voltage have been developed. Low efficiency and short lifetime were main issues to reduce operation voltage when using former generation blue hosts. Therefore new molecular structure of BH was designed to improve both electron and hole mobility and optimize ionization potential (IP) for overcoming the issues. New BHs showed lower voltage and comparable lifetime than former generation BHs. Furthermore, as a result of device optimization using the new BH, low voltage of 3.0V with a high current efficiency of 7.23cd/A, CIE-y of 0.053 at 10mA/cm 2 was successfully achieved in a top-emission device.