Advancements in Perovskite Solar Cell Stability: Mechanisms, Strategies, and Prospects for Commercialisation

Perovskite solar cells (PSCs) rank among the most consequential photovoltaic technologies to emerge this century, having reached certified power conversion efficiencies above 26% for single-junction devices within barely two decades of their first demonstration. Yet this progress has been shadowed by a more stubborn problem: perovskite devices still do not hold up well under the moisture, heat, and sustained illumination they would face outside the laboratory, and this gap in operational stability remains the chief barrier to commercial deployment. This review takes stock of what is currently known about why perovskites degrade and what has been done to slow that degradation, drawing on peer-reviewed literature published mainly between 2018 and February 2026. The dominant degradation pathways—moisture ingress, thermal stress, light-induced phase transformations, and ion migration—are examined both individually and in terms of how they interact with one another. Compositional strategies are assessed in turn, including mixed-cation and mixed-halide formulations, all-inorganic perovskite variants, and reduced-dimensionality quasi-two-dimensional structures, each weighed for its particular trade-offs. Interface and surface passivation methods, improvements to charge-transport layers, and architectural developments—most notably the inverted planar configuration and tandem cell designs—are then reviewed for what they contribute to efficiency and, separately, to durability. The article also considers the practical difficulties of moving from laboratory-scale cells to manufacturable modules, and the parallel effort to establish standardised stability testing protocols that the field can actually agree on. Finally, it looks at two emerging directions: lead-free perovskite chemistries and the use of machine learning to speed up materials discovery. The overall picture that emerges is one of substantial progress, but reaching the twenty-five-year lifetimes expected of commercial photovoltaic modules will require materials, interface, and encapsulation advances to be brought together more coherently, and judged against testing standards the whole field can trust.