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

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 (FAPbI3 ) 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 FAPbI3 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.