Patent ID: 7943245

Claim:
An organic electroluminescent device comprising a luminescent layer containing a luminescent material, an electron-transport layer (ETL1) and an organic thin film layer (ETL2) in this order from an anode side between a pair of electrodes, wherein: the organic thin film layer (ETL2) contains an electron transporting material and has a thickness of 0.01 to 3 nm; the ratio (ETL1/ETL2) of the thickness of the electron-transport layer (ETL1) to the thickness of the organic thin film layer (ETL2) is in the range of 5 to 500; an electron affinity (ETL1 (Ea)) of the electron-transport layer (ETL1) and an electron affinity (ETL2 (Ea)) of the organic thin film layer (ETL2) satisfy the relationship represented by the following equation (2); and the organic thin film layer (ETL2) is adjacent to a cathode layer: ETL 1( Ea )> ETL 2( Ea ) (2) wherein an electron transporting material contained in the electron-transport layer (ETL1) is a metal complex of an 8-quinolinol derivative, and the electron transporting material contained in the organic thin film layer (ETL2) is a metal complex containing at least one of bipyrene, carbazole, imidazopyridine, a derivative thereof, or a derivative of 2-(2-phenolato)imidazopyridine.