Beyond efficiency fever: Preventing lead leakage for perovskite solar cells

Despite the excellent power conversion efficiencies of perovskite solar cells (PSCs), lead toxicity is one of the main concerns for this emerging photovoltaics technology. This review offers basic guidelines for designing encapsulation structures and Pb-absorbing materials to reduce Pb leakages, such as low-cost, high selectivity, and less secondary pollution. This review first illustrates the hazardous effects of Pb toxicity on the environment and the human body. Strategies of preventing lead leakages, such as physical encapsulation, chemical absorption, eco-friendly perovskite materials, and recycling are then discussed. Finally, current challenges and future opportunities to prevent Pb leakage for further industry scaling-up are critically summarized.