Materials for use organic light-emitting device and its

The present invention provides a OLED, in its OLED, the organic thin film layer comprising a single layer or multiple layers is provided between the cathode and the anode, the organic thin film layer comprises at least one light emitting layer, at least one light-emitting layer, (a) the following formula A substituted or an aromatic hydrocarbon group selected from the ten ring), and (b) at least one phosphor, substituted chemical structure represented by one of the partial chemical structure of claim 1, wherein (wherein, R is independently an alkyl substituent having a carbon atom of hydrogen or a 1-3, and at least one ring of the formula has one or more alkyl substituents of the) phosphorescent organic metal having a those containing the complex, including the.