Mechanics-coupled stability of metal-halide perovskites

Metal-halide perovskites (MHPs) possess enormous potential in optoelectronic and semiconductor devices. In these applications, MHPs are often subjected to mechanical stress, resulting in distorted lattice, severe degradation, and catastrophic failure in MHPs and their interfaces. Understanding these mechanics-coupled stability issues is crucial to the durability and, thus, commercial viability of MHP-based devices. Here, we review the impact of mechanical stress on the integrity and robustness of MHP devices to provide insights into mitigating the mechanics-coupled stability issues. We start with an overview of the structure-elastic-property relationship of MHPs, after which we discuss the current understanding of the cohesive and adhesive failures within MHPs and at MHP interfaces forced by mechanical stress, respectively. We further review the chemical stability issues of MHPs and interfaces induced by the mechanical strain. Finally, we summarize the existing strategies to mitigate the mechanics-coupled stability issues and conclude with an outlook of future research directions.