The Promise of Lead-Free Perovskites: Can they Replace Toxic Alternatives in Solar Cells and Lead the Future?

Lead-free perovskites have garnered significant attention as a promising alternative to traditional toxic Pb-containing materials in solar cells. Although lead-based perovskites have achieved high solar energy conversion efficiencies (>25%), their contamination and environmental risks limit their commercial application. Materials based on tin (Sn), bismuth (Bi), antimony (Sb), and germanium (Ge) exhibit the potential to replace lead-based perovskites due to their similar optical and electrochemical properties and lower toxicity. However, key challenges remain, including their lower stability, susceptibility to oxidation (notably Sn2+), and reduced efficiency compared to Pb-based materials. This article reviews recent advancements in the synthesis of lead-free perovskites, methods for improving their structural and functional properties, and their prospects for application in solar cells. The presented review consolidates data on the photovoltaic efficiency, stability, durability, and environmental safety of lead-free perovskites. It discusses their future market potential, emphasizing their environmental friendliness, wide applicability in solar cells, light-emitting devices, neuromorphic systems for artificial intelligence, and microelectronics, as well as scalable production methods that have been developed. The need for further research to optimize their properties and scale up technologies for industrial applications is highlighted. The analysis demonstrates that lead-free perovskites hold substantial promise as a foundation for the next generation of solar cells, providing an environmentally clean and sustainable solution for renewable energy. Nonetheless, addressing the technological challenges related to their stability and scalability is critical for unlocking their full potential.