Core–Shell Engineering of CsPbBr 3 Nanocrystals: Structures, Properties, and Applications

CsPbBr 3 nanocrystals (CPB NCs), an all‐inorganic halide perovskite, have demonstrated high efficiency and significant commercialization potential in fields such as light‐emitting diodes, solar cells, photodetectors, lasers, and bioimaging. However, the instability of CPB NCs in ambient environments remains a major challenge that must be addressed before their widespread commercial applications. Core–shell structural engineering of CPB NCs has been widely employed to mitigate the impacts of external environmental factors, significantly enhancing long‐term stability against moisture, thermal, and oxygen. A protective shell layer covering CPB NCs prevents direct exposure to these environmental factors, providing excellent stability. This review summarizes recent advancements and challenges in CPB NCs‐based core–shell materials, systematically analyzing how shell material types and bandgap structures influence luminescence stability. The energy band structure and configuration of CPB NCs‐shell are discussed in detail, and the classification of shell types, such as perovskite and its derivatives, oxide shells, and polymer shells in single‐layer configurations, is reviewed. Special attention is given to the applications of the CPB NCs‐based core–shell materials with enhanced stability. Finally, the main challenges and further research directions for the core–shell structure of CPB NCs are discussed, with the aim of promoting the development of stable metal halide perovskite materials in the future.