White Stacked Electrophosphorescent Organic Light‐Emitting Devices Employing MoO3 as a Charge‐Generation Layer

White stacked electrophosphorescent organic light-emitting devices employing three metallorganic phosphors in a compound emission layer (see Figure) are demonstrated. They show an external efficiency of 51 % and power efficiency of 20.7 lm W–1 at practical illumination intensities. A transparent MoO3 film between two adjacent electrophosphorescent elements efficiently injects charge into the stacked elements.