An electroluminescent device comprises a cathode, an anode, and has therebetween a light emitting layer (LEL), the device further containing an electron transport layer (ETL) comprising an anthracene compound on the cathode side of the LEL and an organic electron injection layer (EIL) between the ETL and the cathode comprising a phenanthroline compound, wherein the thickness of the EIL and LEL are such that the ratio of the thickness of the EIL to LEL is greater than 0.125.