33.3: Distinguished Student Paper : Improved Blue Phosphorescent OLEDs with a Linearly‐Graded Mixed Host Architecture

A blue PhOLED with a linearly‐graded mixed host architecture is compared to a uniformly‐mixed host device. We show that the recombination region is moved into the interior of the emissive layer and results in higher efficiency through avoiding quenching of the phosphor by species in the electron transporting layer.