Radical Polymers for Organic Electronic Devices: A Radical Departure from Conjugated Polymers?

Abstract Radical polymers are aliphatic or nonconjugated polymers bearing organic robust radicals as pendant groups per repeating unit. A large population of the radical redox sites allows the efficient redox gradient‐driven electron transport through the polymer layer by outer‐sphere self‐exchange reactions in electrolyte solutions. The radical polymers are emerging as a new class of electroactive materials useful for various kinds of wet‐type energy storage, transport, and conversion devices. Electric‐field‐driven charge transport by hopping between the densely populated radical sites is also a remarkable aspect of the radical polymers in the solid state, which leads to many dry‐type devices such as organic memories, diodes, and switches.