Highly Efficient, Conventional, Fluorescent Organic Light‐Emitting Diodes with Extended Lifetime

Abstract Highly efficient, yellow‐fluorescent organic light‐emitting diodes with a maximum external quantum efficiency exceeding 25.0% and extended lifetime are reported using iridium‐complex sensitizers doped in an exciplex host. Energy transfer processes reduce the lifetime of the exciplex and excitons on the Ir complexes and enable an excited state to exist in a conventional fluorescent emitter, thereby increasing device lifetime. The device stability depends on the location of the excited state.