Toward Efficient and Stable Perovskite Solar Cells: Choosing Appropriate Passivator to Specific Defects

With a certificated record efficiency of 25.2%, organometal halide perovskite (OHP) solar cells have experienced unprecedentedly rapid development in the past decade due to their extraordinary photoelectronic properties. However, because of the rapid processing conditions and complex precursor compositions, there are a large number of defects in polycrystalline OHP films, including point defects and 2D defects along grain boundary and on the surface. Unfortunately, these defects serve as the nonradiative recombination centers and exert negative effects on the degradation and performance of OHP layers, heavily limiting their further application for efficient photovoltaic devices. Herein, the formation origin of various defects as well as their detrimental effects on the efficiency and stability of perovskite solar cells (PSCs) are discussed, and recent passivation strategies for specific defects to minimize defect state density in the perovskite films are summarized. Finally, a brief outlook on the development trend of future passivation engineering is provided for deeper understanding of efficient and stable PSCs.