Shape-Deformable Self-Healing Electroluminescence Displays

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.