The evolution of electrical, optical, and mechanical properties of CsPbBr3 perovskites during continuous phase transitions

CsPbBr3 perovskite has garnered significant attention due to its stable crystal structure and excellent optoelectronic properties. This study establishes an atomically correlated model to describe the phase transition process of CsPbBr3. Utilizing density functional theory (DFT), the research systematically explores the structural evolution, electronic structure, optical properties, and mechanical performance of CsPbBr3 perovskite during the phase transition. Comparative analysis reveals that the newly developed model in this study shows good consistency with results reported in the literature, validating the model's effectiveness and accuracy. Further analysis indicates a significant phase transition barrier between the tetragonal and orthorhombic phases, suggesting that low-temperature crystallization methods are more suitable for the preparation of CsPbBr3 single crystals or thin films. Notably, despite the distortion of Pb-Br-Pb bonds among different phase structures, the calculated band structures and optical properties exhibit a high degree of similarity, indicating that the optoelectronic properties of CsPbBr3 remain relatively stable across different phases, suggesting a wide operational temperature range. Moreover, an in-depth analysis of the mechanical properties shows that CsPbBr3 exhibits good toughness throughout the phase transition process, with the orthorhombic phase achieving optimal toughness, thermal shock resistance, and machinability. This finding not only provides theoretical support for the application of CsPbBr3 under extreme environmental conditions but also lays a solid foundation for further optimization of its performance and expansion of its application areas.