Lead-free alternatives and toxicity mitigation strategies for sustainable perovskite solar cells: a critical review

Abstract

The growing global energy demand has prompted an increase in research into renewable energy conversion technologies. Although lead-based perovskite solar cells (PSCs) offer high efficiency as well as low manufacturing costs, the toxicity of the material is still a serious hurdle to their commercialization and widespread adoption. Amid ongoing efforts to develop lead-free perovskites, over the last few years, growing attention on mitigating the toxicity of lead by inhibiting the leakage of lead from PSCs has been observed. This review discusses the potential replacement of lead from PSCs and explores various approaches to mitigate lead leakage from PSCs. In addition, researchers expect that tin, germanium, antimony, bismuth and their combination-based perovskites (PVSKs), as well as other PVSK structures like halide double PVSKs, chalcogenide PVSKs, and metal-free organic perovskites, will be alternatives to lead-based PVSKs for the development of effective lead-free PSCs. Moreover, along with efforts to develop lead-free PSCs, researchers are also keen on supporting highly performing lead-based PSCs by addressing the issue of lead contamination by means of exploring strategies for lead confinement and lead recycling in Pb-based PSCs, since complete removal of lead from PSCs may require rigorous research and significant time. Therefore, technologies that increase the public acceptability of the present Pb-based PSCs require further development.