An OLED device comprises a cathode, a light emitting layer and an anode, in that order, and comprises; (i) a further layer located between the cathode and the light emitting layer, containing (a) 10 vol % or more of a carbocyclic fused ring aromatic compound, and (b) at least one salt or complex of a Group IA, IIA, IIIA and IIB element of the Periodic Table, and (ii) an additional layer, located between the anode and the light emitting layer, containing a compound of Formula (8) wherein: each R independently represents hydrogen or an independently selected substituent, at least one R representing an electron-withdrawing substituent having a Hammett's sigma para value of at least 0.3. Such devices exhibit reduce drive voltage while maintaining good luminance.