Comparative toxicity of potential leachates from perovskite and silicon solar cells in aquatic ecosystems

Globally, perovskite solar cells (PSCs) represent a third-generation photovoltaic technology that is being increasingly implemented and commercialized. However, the biological impacts of leachates from PSCs are poorly understood. Therefore, the aim of this study was to investigate the ecotoxicity of PSC leachates compared with that of commercial Si-based solar cell (SBSC) leachates. We performed leaching assessments and aquatic bioassays using internationally recommended test species and measured and compared the ecotoxicity of PSC and SBSC leachates. As a result of the leaching analyses, Si, Pb, and Al were found to be the most leached elements from broken PSCs and SBSCs. The bioassays indicated that polycrystalline SBSC (p-Si) and monocrystalline SBSC (m-Si) leachates were more toxic to fish embryos than the PSC leachates and that water fleas were sensitive to m-Si leachates, but less sensitive to PSC and p-Si leachates. In addition, principle component analyses indicated that the ecotoxicity of solar cell leachates was related to either the Pb or Si content. This is the first comparative study of the potential ecotoxicity of PSC and SBSC leachates in aquatic ecosystems, and the results of which can be used in the environmentally safe commercialization of solar cells.