Greenish-yellow electroluminescent devices using a novel dihydroquinazolinone derivative as emitting layer

We report organic electroluminescence (EL) devices based on a novel emissive molecule, 2-[4'-(N, N-dimethylaminophenyl)]- 2,3-dihydroquinazolin-4(1H)-one (MAPQ). A three-layer structure consisting of MAPQ as emissive layer sandwiched between a hole transporting layer, N,N'-diphenyl-N,N'-bis(3-methylphenyl)- 1,1-biphenyl- 4,4'-diamine(TPD), and an electron transporting layer, tris(8-hydroxyquinolinato) aluminium (Alq(3)), ITO/TPD/MAPQ/Alq(3)/Al gave rise to a greenish-yellow peak located at around 538 nm, with coordinates (x = 0.447 and y = 0.510) in accordance with the Commission Internationale de L'Eclairage. An EL external quantum efficiency (eta (ext)) of 0.07% at 125 A m(2) and a brightness of 992 cd m(-2) were observed, and the eta (ext) is nearly constant or stable over a wide range of current densities (3-300 A m(-2)).