Tri (p-terphenyl-4-yl) amine as a novel blue-emitting material for organic electroluminescent devices

A novel amorphous molecular material, tri(p-terphenyl-4-yl)amine (p-TTA), was found to function as a morphologically and thermally stable blue-emitting material for organic electroluminescent (EL) devices. A double-layer EL device consisting of an emitting layer of p-TTA and a hole-transport layer of 1,3,5-tris[N-(4-diphenylaminophenyl)phenylamino] benzene sandwiched between an alloy of magnesium and silver (about 10:1) and indium-tin-oxide (ITO) electrodes emitted bright blue light resulting from p-TTA. The EL device exhibited a maximum luminance of about 350 cd m−2 at a driving voltage of 13 V. The external quantum efficiency was estimated to be 0.4%.