Patent ID: 8766291

Claim:
An organic light emitting device comprising: a cathode; a blue-emitting sub-element comprising an emissive layer comprising a phosphorescent blue emissive material; a charge-generating layer; a green-emitting sub-element comprising an emissive layer comprising a phosphorescent green emissive material; a charge-generating layer; a red-emitting sub-element comprising an emissive layer comprising a phosphorescent red emissive material; and an anode; wherein each of the sub-elements has a charge balance factor of about 0.9 to 1, wherein the emissive layers of each sub-element are within about 20% of the distance to an antinode for that emitter, wherein each of the sub-elements is separated by a charge-generating layer, and wherein a combined emission of the emissive materials gives a white emission from the device.