| abstract |
A varnish containing a charge-transporting organic material and a solvent is used as a charge-transporting varnish. The charge-transporting organic material is composed of a charge-transporting substance comprising a charge-transporting monomer, or charge-transporting oligomer or polymer having a number average molecular weight of 200 to 500,000, or is composed of such a charge-transporting substance and an electron- or hole-accepting dopant substance. The solvent contains at least one type of high-viscosity solvent having a viscosity of 10 to 200 mPa·s at 20° C. The charge-transporting substance or the charge-transporting organic material is dissolved or uniformly dispersed in the solvent. The varnish has a high uniform film forming capability even in a system using a charge-transporting substance of low molecular weight and a charge-accepting dopant substance. When the varnish is used in, particularly an OLED device or PLED device, excellent EL device characteristics, namely a low drive voltage, a high luminance efficiency, and a long life are realized. |