Electroluminescent devices with nitrogen bidentate ligands

摘要

An OLED device comprises a cathode, an anode, a light-emitting layer, and, between the cathode and the light emitting layer, a non-emitting layer containing a metal complex of "n" bidentate ligands having Formula (1): wherein: M represents Ga, Al, Be, or Mg; n is 3 in the case of Ga or Al and 2 in the case of Be or Mg; and each Z^a and each Z^b is independently selected and each represents the atoms necessary to complete an unsaturated ring; z^a and Z^b are directly bonded to one another provided Z^a and Z^b may be further linked together to form a fused ring system; provided that the light emitting layer is substantially free of said metal complex present in the non-emitting layer. Such a device exhibits improved luminous efficiency.