| abstract |
An organic electroluminescent device comprising an anode (2), a positive-hole transport layer (4) of organic compound, an emitting layer (3) of organic compound and a cathode (1) which are laminated in sequence, the emitting layer comprises a pyrimidopyrimidine derivative of the formula 1n n where R₁ - R₄ are independently hydrogen atom, halogen atom and functional groups represented by formula 2.n n where R₅ and R₆ are independently hydrogen atom, alkyl group, aryl group, or R₅ and R₆ taken together comprises the atoms or groups necessary to complete a cycloalkyl or hetetocylic ring. n This device has a high luminance and high emission efficiency. |