Stability Issue of Perovskite Solar Cells under Real‐World Operating Conditions

Organic–inorganic lead halide perovskites solar cells (PSCs) show great potential in the photovoltaic system, reaching overall power conversion efficiencies (PCE) up to 25.2%. The rapid increase of PCE in PSCs has made them the rising star of the photovoltaics world, with great interest to the academic community. Long‐term stability under working environments remains a significant challenge for the commercialization of PSCs, particularly those using inorganic–organic halide lead perovskite absorbers. In this regard, only the devices that can maintain long‐term stability under conditions of temperature, humidity, and UV irradiation can be called stable solar cells. This Review highlights the sources for the chemical instability problems in conventional CH3NH3PbI3‐based perovskite solar cells from humidity instability, phase instability, thermal instability, and ion migration. In pursuit of highly stable PSCs, this article also discusses the strategies to stabilize PSCs through both external and internal aspects without sacrificing the PCE, specifically including additive engineering with surface passivation and composition engineering. Stability is the most significant issue to limit the development of perovskite solar cells. Based on the analysis of light, humidity, and water stability, this Review directs the way to improving the stability of perovskite solar cells under real‐world operating conditions.