Water‐Influenced Perovskite Materials: Crystal Transition, Stability Regulation, and Applications

Halide perovskite materials have captured increasing interest for optoelectronic applications due to their excellent optical properties and cost‐effective solution processibility. Despite the great advances in perovskite materials and their devices, the ionic nature of perovskites renders them instability, especially when exposed to water. Interestingly, recent studies have demonstrated that trace amounts of water can regular perovskite growth dynamics and facilitate surface reconstruction, offering new opportunities for material design and performance improvement. This review presents a comprehensive overview of the recent research progress in water‐influenced perovskite materials. First, the impact of water on crystal transformation, morphological regulation, and optical properties is discussed. Next, water‐involved strategies for improving water‐stable perovskites materials are outlined. Subsequently, the applications of water‐influenced perovskite materials in light‐emitting diodes, solar cells, and cellular imaging are highlighted. Finally, the practical challenges and future directions for water‐influenced perovskite materials is critically examined to inspire further exploration in this field. It is believed that the photoelectric performance of perovskite materials and devices can be effectively enhanced through reasonable water treatment.