How to accelerate outdoor ageing of perovskite solar cells by indoor testing

Abstract Halide perovskite is a material that shows great promise in producing renewable energy. It offers one of the most efficient forms of photovoltaics for large-scale production. However, while perovskite solar cell devices are more efficient than many established technologies, their long-term stability outdoors is still being determined. Most studies have tested the stability of perovskite solar cells by keeping them under continuous illumination at maximum power point tracking for hundreds to a few thousand hours. Increasing the temperature has been proposed to accelerate degradation and project data collected relatively quickly to years of outdoor operations. However, PSCs undergo extensive degradation recovery during the resting time in dark and transient dynamics during the illumination they experience in day-night cycling. Therefore, an ageing protocol based on maximum power point tracking under continuous illumination cannot enable quantitative prediction of outdoor performances. To address the challenge of predicting the outdoor stability of perovskite solar cells, we have demonstrated how ageing perovskite solar cells under light/dark cycling that reproduces outdoor functioning with controlled temperature and illumination conditions allows a predictive analysis. Our ageing protocol can accelerate the degradation of perovskite solar cells up to 46 times, i.e. 6 months of indoor testing can reproduce the standard 25 years of outdoor functioning. This result will speed up the studies of perovskite solar cells' stability and their commercialisation.