US Patent 11825687 Organic light emitting device

An OLED device comprises a substrate, a first electrode positioned over the substrate, a second electrode positioned over the first electrode, at least one emissive layer positioned between the first and second electrodes in a first region of the OLED device, and a multilayer dielectric reflector stack, comprising a plurality of dielectric reflector layers positioned between the substrate and the first electrode, wherein the multilayer dielectric reflector stack is configured to form an optical cavity with the emissive layer having a Purcell Factor of at least 3.