Flexible perovskite photodetector with room-temperature self-healing capability without external trigger

Abstract

Flexible perovskite photodetectors (FPDs) are promising for novel wearable devices in bionics, robotics and health care. However, their performance degradation and instability during operations remain a grand challenge. Superior flexibility and spontaneous functional repair of devices without the need for any external drive or intervention are ideal goals for FPDs. Herein, by using phenyl disulfide instead of alkyl disulfide as a crosslinking agent, disulfide bonds with lower bond energy are introduced, thus endowing the polyurethane network (SCPU) with the ability of self-healing at room temperature. SCPU is filled to the grain boundary of perovskite film, which not only improves the crystal quality of perovskite and mechanical stability of FPD but also enables FPD to self-heal at room temperature. As a result, the as-prepared FPD exhibits a superior responsivity of 0.4 A W⁻¹, a high specific detectivity of 2.5 × 10¹¹ Jones and 2 μs fast response time in a self-powered mode. More importantly, the FPD still retained 91% of the initial photo responsivity after 9000 times of bending upon cyclic healing. This polymer doping strategy provides an effective solution for stable operation and room-temperature self-healing for FPDs.