Moisture‐Triggered Self‐Healing Flexible Perovskite Photodetectors with Excellent Mechanical Stability

Abstract Flexible devices are urgently required to meet the demands of next‐generation optoelectronic devices and metal halide perovskites are proven to be suitable materials for realizing flexible photovoltaic devices. However, the tolerance to moisture corrosion and repeated mechanical bending remains a critical challenge for flexible perovskite devices. Herein, a self‐healing formamidinium lead iodide (FAPbI 3 ) film is fabricated to cure mechanical damage by absorbing moisture from the surrounding environment. A poly(vinyl alcohol) microscaffold is designed not only to stabilize the black phase of the FAPbI 3 film but also to endow it with self‐healing ability in a humid environment. The photodetector based on a self‐healing film exhibits a high responsivity of 11.3 A W −1 and recovers to over 90% of the initial responsivity after the self‐healing process. This work provides an effective self‐healing strategy to stabilize the operation of flexible perovskite devices under normal high‐humidity environmental conditions.