Life cycle toxicity and reduction potential analysis of perovskite photovoltaic technology.

Perovskite solar cells (PSCs), an emerging photovoltaic technology promising lower cost and higher efficiency, have been developed rapidly. However, the widespread use of lead in current PSCs raises toxicity concerns, prompting interest in lead-free alternatives. Despite this, comprehensive life cycle assessments of toxicity impacts across PSC types remain limited, potentially leading to biased technology choices and environmental harm. Here we conducted a comparative life cycle toxicity impact assessment (human toxicity, aquatic ecotoxicity, and terrestrial ecotoxicity) for representative lead-containing and lead-free PSCs. Results indicated that lead-free PSCs could exhibit higher toxicity impacts and lower reduction potentials compared to lead-containing PSCs. The inappropriate disposal of lead-containing PSCs elevated human toxicity and terrestrial ecotoxicity by 0.5-35.8 times, primarily due to heavy metals leakage, especially lead. Among all the life cycle stages, the supply chain stage contributed 2.7 %-63.5 % of human toxicity and 38.6 %-99.9 % of ecotoxicity, mainly from electricity generation and raw materials production. In contrast, the primary toxicity driver for lead-free PSCs was CuSCN production. Scenario analysis suggests that improving module efficiency and extending lifetime to theoretical maximums could reduce the toxicity impacts by 99 %. Transitioning to a cleaner electricity structure would result in a reduction of impacts by 2.5 %-96.6 % for lead-containing and 1.2 %-1.7 % for lead-free PSCs. This study provides critical insights into the life-cycle toxicity impacts of PSCs technologies and offers guidance for more sustainable PSC development.