Recent Trends and Challenges in Lead-Free Perovskite Solar Cells: A Critical Review

The world's rising energy demand has accelerated research into renewable energy conversion technologies. Lead-based perovskite materials have drawn the attention of researchers around the globe. These cells have the potential to improve the efficiency of solar energy conversion, and they are being developed as a replacement for traditional solar cells (SCs). The favorable electrical and optical properties of lead make it a promising candidate for optoelectronics and photovoltaic applications. However, the toxic nature of lead and its low material stability hamper its future market prospects. Therefore, researchers are focusing on alternatives to lead, such as developing environmentally friendly perovskite SCs. This review summarizes the recent developments in nontoxic, lead-free perovskite materials for SCs. Lead-free perovskite materials like Sn, Ge, Sb, Bi, their combinations, and other perovskite materials such as double perovskites are being explored for photovoltaic SC fabrication. Their advantages, stability, and technical issues are discussed in this review. Based on this review, it seems that more work needs to be done to develop alternative materials for future lead-free perovskite SCs.