Red-light-emitting organic electroluminescent devices with bisanil dye as emitter

Double-layer organic thin film electroluminescent (EL) devices having red emission have been constructed using bisanil dyes. The basic structure of the EL device consisted of a hole-transport layer and a luminescent layer between the indium-tin-oxide (ITO) glass and magnesium electrodes. The hole-transport layer was a N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD)-doped poly(N-vinylcarbazole) (PVK) film. The luminescent layer consisted of a host material, 8-hydroxyquinoline aluminum (Alq(3)), and bisanil dye as the dopant. The full width at half maximum (FWHM) of the PL and EL spectra of two bisanil dyes is as narrow as 50nm. Among the two materials studied by us, the N,N'-bis[4-(N,N-dimethylamino)-benzylidene]diaminomaleonitrile (BAM) showed a better EL performance. A bright pure red light with a peak at 620 nm and a maximum luminance of 6230 cd/m(2) was observed.