Degradation pathways in perovskite solar cells and how to meet international standards

Commercialization is widely believed to be achievable for metal halide perovskite solar cells with high efficiency and low fabrication cost. However, stability remains a key obstacle for them to compete with established photovoltaic technologies. The photovoltaic community relies on the International Electrotechnical Commission (IEC) standard for the minimum stability assessment for any commercialized solar cell. In this review, we summarize the main degradation mechanisms of perovskite solar cells and key results for achieving sufficient stability to meet IEC standards. We also summarize limitations for evaluating solar cell stability and commercialization potential within the framework of the current IEC standard, and discuss the importance of outdoor testing.