Shape‐Deformable Self‐Healing Electroluminescence Displays

Abstract Self‐healing electronic materials can substantially enhance the lifetime of a device as they can self‐repair mechanical damages, thereby recovering their initial electronic performance similar to human skin. Despite the development of various self‐healing electronic components such as electrodes and semiconducting carrier transport layers, self‐healing electroluminescence (EL) layers suitable for deformable displays, which require both high stretchability and self‐recovery function, have been rarely demonstrated. Herein, shape‐deformable and self‐healing EL displays (SSELDs) are presented. Light‐emitting materials are fabricated by adding a certain amount of a plasticizer, Triton X‐100, to elastomeric poly(urethane) containing light‐emitting Cu‐doped ZnS microparticles to obtain a viscoelastic composite that undergoes facile shape‐deformation and recovery. A capacitive SSELD exhibits frequency‐dependent field‐induced light emission under alternating current (AC). Color mixing and tuning of EL is conveniently achieved by mechanically mixing two or more Cu‐doped ZnS microparticles with different EL characteristics. More importantly, an SSELD self‐recovers its EL within few minutes of electrical failure. Further, the AC EL device endures more than 100 cycles of failure‐recovery operations. By combining with a shape‐deformable ionic liquid, a novel fiber display that exhibits excellent shape‐deformable and self‐healing EL performance is demonstrated.