White organic electroluminescent devices fabricated using ink-jet printing method

White organic electroluminescent devices fabricated using the ink-jet printing method have been investigated. The solution of organic materials was composed of a hole transport material, an electron transport material and an emission material dissolved in 1,2-dichloroethane. A maximum luminance of 3,600 cd/m2, maximum external quantum efficiency of 4.15% and Commission International de l'Eclairage chromaticity of (x,y)=(0.29,0.33) have been obtained from the device with poly(9-vinylcarbazole) as host material, 2,5-bis(1-naphthyl)-1,3,4-oxadiazole as electron transport material, a mixture of perylene and 4-dicyanomethylene-6-cp-julolidinostyryl-2-tert-butyl-4H-pyran as emission materials, and cesium as cathode.