US Patent 7564181 Performance enhancement layer for OLED devices

An organic light-emitting device includes a substrate; a first electrode and a second electrode positioned relative to the substrate in which at least one of the electrodes is the transparent electrode; an organic light-emitting element including at least a light-emitting layer disposed between the two electrodes; and a performance enhancement layer disposed between the two electrodes; wherein the performance enhancement layer is high index and has a thickness of at least 20 nm.