Stabilization and Regulatory Strategies for All‐Inorganic Cesium Lead Halide Perovskite Black Phase

ABSTRACT All‐inorganic CsPb X 3 perovskites (PVK) are regarded as a key solution to the intrinsic instability of organic–inorganic hybrids due to their excellent thermal stability. However, the photoactive black phase is thermodynamically metastable at room temperature because of a low Goldschmidt tolerance factor, and high‐density defects within the bulk and at surfaces severely limit device performance. This review systematically outlines the research background and advantages of all‐inorganic CsPb X 3 PVK. It further provides an in‐depth analysis of the mechanisms governing phase transition and defect evolution from the perspectives of thermodynamics and crystallization kinetics. Furthermore, we discuss optimization strategies for enhancing the efficiency and phase stability of all‐inorganic CsPb X 3 PVK, and we also consider their potential for large‐scale and commercial manufacturing.