A blended layer MEH-PPV electroluminiscent device incorporating a new electron transport material

Single layer organic light-emitting devices containing both poly[2-(2-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene] (MEH-PPV) as an emissive polymer and a new electron transport (ET) material, 2,5-bis[5-(4-tert-butylphenyl)-2-pyridyl]-1,3,4-oxadiazole, have been prepared. These devices, produced by spin coating the organic material, showed higher quantum efficiencies and lower turn-on voltages than dual layer devices, fabricated by spin coating and thermal evaporation. The single layer structure has the advantage of an easy manufacturing process. An external quantum efficiency of 0.26% was obtained for a device incorporating 20% by weight of the electron transport material.