A Review of the Strategies Used in the Recovery and Passivation of Lead in Lead‐Based Perovskite Solar Cells: Balancing Device Efficiency, Toxicity, and Environmental Sustainability

ABSTRACT Lead‐based perovskite solar cells (LPSCs) have emerged as one of the most promising photovoltaic (PV) technologies due to their exceptional high light‐harvesting capabilities, tunable bandgap, long carrier diffusion lengths, and impressive power conversion efficiencies (PCEs) exceeding 27%. However, the inherent toxicity and environmental risks of lead present a critical obstacle to their large‐scale deployment. Accordingly, this review aims to address the performance–sustainability gap of LPSCs by systematically evaluating recent strategies for lead passivation and recovery that enhance device efficiency while minimizing ecological impact. Using the traditional literature review approach, we synthesize current findings on chemical, physical, and interface‐level techniques employed to stabilize or neutralize lead within the perovskite structures. Surface passivation methods, such as molecular chelation, ligand engineering, and two‐dimensional (2D) capping layers, are explored in detail, accompanied by relevant reaction mechanisms and schematic illustrations. In parallel, we present experimental lead recovery techniques, including solvent‐based extraction, electrochemical separation, solid‐state capture, and membrane filtration, supported by process flow diagrams and tabulated reaction pathways. Environmental aspects are critically addressed through life cycle assessments (LCAs), end‐of‐life (EoL) considerations, and environmental footprint analysis. Circular economy approaches tailored to LPSC technology, such as closed‐loop recycling, material recovery systems, and sustainable encapsulation, are also examined. Representative lead‐based perovskites, including MAPbI 3 , FAPbBr 3 , and mixed‐cation variants are discussed in terms of structure–property relationships and stability. A detailed comparison between lead‐ and tin‐based perovskites is also provided, showcasing their respective efficiencies, stabilities, and environmental trade‐offs through comprehensive performance tables. Balancing the high efficiency of LPSCs with environmental responsibility is essential for their commercial viability. This review highlights that strategic lead passivation and recovery not only reduce toxicity but also improve device performance and long‐term stability. Going forward, critical focus on material innovation, recycling frameworks, and sustainability assessments is key to the responsible advancement of lead‐based PV technologies. Key Points Introduction : Lead management for sustainable high performing solar cell modules. Methodology : Traditional review on lead‐baed perovskite solar cells. Quantitative Assessment of Lead : Chlorobenzene and γ‐butyrolactone (GBL) can dissolve and recrystallize MAPbI 3 with yields approaching 87%. Strategies for Blocking Lead : Two primary approaches to address this challenge are chemical passivation and the use of physical barriers. Self‐Healing and Nanocomposite Encapsulation : Advanced encapsulation materials such as polyurethane can prevent release of lead into the environment. Lead Recovery : This can be achieved effectively by electrochemical methods. End of Life of Lead : This alongside life‐cycle asessment is very important for environmental sustainability. Circular Economy Model : This informs the principle that nothing should go to waste. Lead‐based Perovskites : This is a comparative analysis meathyl ammonium lead‐based and Formamidinium lead‐based perovskite solar cells. Comparative Analysis of Lead‐based and Tin‐based Perovskite Solar Cells : This compares effieicy and stability of lead and tin‐based photovoltaics. Future Outlook : Lays down the roadmap for adopting lead‐baed perovskites. Conclusions : Overcoming the degradation and stability challenges of lead‐based perovskite solar cells offers promise for the adoption of high performance solar cells.