Emission characteristics of electroluminescent devices using molecularly-doped polymer films

Electroluminescent (EL) devices made of molecularly-doped polymer films in which the component dyes and their compositions were systematically varied were fabricated. A diamine derivative, TPD, as a hole transport material and an oxadiazole derivative, BND, as an electron transport material were employed. A naphthostyryl derivative as an emitter material with hole transport capability, a phthalolperinone derivative as an emitter material with electron transport capability, and coumarin-6 as an emission centre were used. Three types of single-layer EL devices were prepared. The emission characteristics of the EL devices with different dye combinations and compositions were measured and compared. The EL efficiencies were found to be largely dependent on the dye combinations and their composition.