| abstract |
The present invention provides an OLED in which an organic thin film layer comprising a single layer or plural layers is provided between a cathode and an anode, where the organic thin film layer comprises at least one light emitting layer, and the at least one light emitting layer comprises (a) a host material represented by the following Formula (1): Ra—Ar 1 —Ar 2 —Rb (1) where Ar 1 , Ar 2 , Ra and Rb represent a substituted or unsubstituted benzene ring or a condensed aromatic hydrocarbon group selected from a substituted or unsubstituted naphthalene ring, chrysene ring, a substituted or unsubstituted fluoranthene ring, triphenylene ring, a substituted or unsubstituted phenanthrene ring, a substituted or unsubstituted benzophenanthrene ring, a substituted or unsubstituted dibenzophenanthrene ring, a substituted or unsubstituted benzotriphenylene ring, a substituted or unsubstituted benzochrysene ring, a substituted or unsubstituted picene ring and a substituted or unsubstituted benzofluoranthene ring; and (b) at least one phosphorescent material comprises a phosphorescent organometallic complex having a substituted chemical structure represented by one of the following partial chemical structures represented by the formulas: wherein each R is independently hydrogen or an alkyl substituent having 1-3 carbon atoms, and wherein at least one ring of the formula has one or more of said alkyl substituent. |