Achieving Resistance against Moisture and Oxygen for Perovskite Solar Cells with High Efficiency and Stability

Realization of high efficiency along with long-term stability of perovskites solar cells has been a goal of researchers in this field. Breakthroughs in efficiency have been achieved in the past decade, exceeding those of most thin film solar cells. However, the challenge of degradation and instability of perovskite solar cells is currently the bottleneck for their real-life application. Extensive research has been conducted to achieve simultaneously high efficiency and high stability, leading to considerable progress in device performance. A significant source causing degradation is the ingression of external materials, such as moisture and oxygen. In this review, the mechanisms of moisture and oxygen degradation occurring in perovskite absorber and charge transporting layers are interpreted. Primary approaches to simultaneously achieve high efficiency and high stability focus on encapsulation, interfacial layer engineering, process engineering, ion engineering, and dopant and alternative engineering. In brief, we review the materials development and engineering strategies to improve performance and identify the obstacles that hinder the realization of high stability along with high efficiency.