Patent ID: 10233337

Abstract:
A charge-transporting thin film having excellent flatness can be obtained with good repeatability using the charge-transporting varnish of the present invention, which contains: a charge transportation substance comprising a charge-transporting monomer or a charge-transporting oligomer or polymer having a number-average molecular weight of 200-50,000, or a charge transporting material comprising the charge transportation substance and a dopant substance; and a mixed solvent including at least one type of good solvent and at least one type of poor solvent; the absolute value of the boiling point difference ΔT° C. of the good solvent and the poor solvent satisfying the relation |ΔT|<20° C.; the viscosity at 25° C. being 7.5 mPa·s or less; the surface tension at 23° C. being 30.0-40.0 mN/m; and the charge-transporting material being dissolved or uniformly dispersed in the mixed solvent.