Ultrastable and efficient red organic light emitting diodes with doped transport layers

We demonstrate extremely stable and highly efficient red p-i-n-type organic light emitting diodes (OLEDs) based on an iridium-based electrophosphorescent dye in suitable host materials. The OLEDs reach lifetimes well above 1x10(7) h at 100 cd/m(2) initial luminance and reach at the same time a performance of 12.4% external quantum efficiency. This high lifetime is attributed to a combination of the low current density needed to reach a certain luminance and to the high stability of the materials against both charge carriers and excitons. (c) 2006 American Institute of Physics.