25.2: Invited Paper: Concepts for Highly Efficient White OLEDs

In this paper, we discuss in detail a novel concept for white organic light‐emitting diodes (OLEDs) comprising three different phosphorescent emitters. Its key feature, a matrix‐emitter combination for the blue sub‐emission layer combined with a specific arrangement of the green‐ and red‐emitting layers, leads to very high luminous efficacies. We present the key parameters of this emission layer design that are essential for high efficiencies. Finally, we briefly discuss a second, highly efficient approach for white OLEDs: the triplet harvesting concept. It makes use of a fluorescent blue emitter having benefits for higher device stability and at the same time the potential for 100% internal quantum efficiency.