The present invention relates to efficient organic light emitting devices
(OLEDs) doped with multiple light-emitting dopants, at least one dopant
comprising a phosphorescent emitter, in a thin film emissive layer or
layers. The present invention is directed to an efficient phosphorescent
organic light emitting device utilizing a plurality of emissive dopants
in an emissive region, wherein at least one of the dopants is a
phosphorescent material. Thus, the present invention provides an organic
light emitting device comprising an emissive region, wherein the emissive
region comprises a host material, and a plurality of emissive dopants,
wherein the emissive region is comprised of a plurality of bands and each
emissive dopant is doped into a separate band within the emissive region,
and wherein at least one of the emissive dopants emits light by
phosphorescence.