Understanding the Long-Term Instability of Metal Halide Perovskite Solar Cells

The low longevity of perovskite solar cells and modules remains to be a major roadblock after years of research despite the high efficiencies of perovskite solar cells demonstrated in academic laboratories and companies. Although relatively good operational stabilities have been frequently reported, the outdoor stability in real operation stability from public data is far below what is required for 25-year operation. Understanding the underlining mechanisms of device degradation or module degradation over long term under realistic operational conditions is crucial before inventing strategies to enhance their stability. Many studies already show that the degradation of perovskites solar cells is much more complicated than silicon and other types of thin film solar cells. Here I will report our progress in understand the mechanisms of solar cell degradation over relatively long term under different stressors including reverse bias, high temperature and UV light. I will also report our strategies to improve the projection lifetime to over 30 years.