Enhancing Thermal Stability of Perovskite Film for durable Solar Cells.

The practical application of metal halide PSCs (PSCs) is badly impeded by their long-term stability concerns, with the issues primarily rooted in the perovskite film. In real-service environments, PSCs endure multiple external factors, light, heat, humidity, and oxygen. Among them, thermal instability represents a particularly severe and fundamental challenge, since heat acts not only as a direct degradation driver but also as a potent accelerator of other degradation pathways. Herein, this review discusses the thermal degradation mechanisms of perovskite from the perspectives of phase transition, materials decomposition, thermal stress, passivation failure and thermal coupled effect, with the latter two aspects emphasized. Then, the review outlines the effective strategies for enhancing the thermal stability of perovskite film and corresponding solar cells, including A-site cation component engineering, crystal facet engineering, dimensional engineering, stress regulation and ion migration inhibition. Finally, perspectives on the future researches for advancing the development of thermally stable devices are proposed, aiming to offer referable routes for accelerating the PSCs industrialization.