Abstract
Because of their straightforward manufacture and exceptional photovoltaic efficiency, perovskite solar cells (PSCs) have quickly become appealing rivals in the photovoltaic sector. The residual strain, which prevents their practical use, keeps the efficiency and long-term stability below practical bounds. Herein, the causes of strain in metal-halide perovskites that are pertinent to photovoltaic applications, as well as how strain affects the materials' physical characteristics and solar performance and how to control it, are discussed. Finally, a perspective on future strain engineering to support robust and effective PSCs is proposed. This review provides a comprehensive understanding of strain from origins, effects, to regulation, which would enhance the research enthusiasm on strain engineering to drive further improvements in performance especially stability of PSCs toward commercialization.