Assessment of the environmental and human health impact in the synthesis and processing of metal halide perovskite active layers using GVL

Metal halide perovskites (MHPs) offer a potential alternative to crystalline silicon solar cells in terms of efficiency. Despite the impressive reported efficiencies exceeding 26%, the widespread uptake of perovskite solar cells still faces significant challenges, such as the use of lead precursors and hazardous reaction and processing media for their production. In fact, commonly used solvents such as N,N-dimethylformamide (DMF) or γ-butyrolactone (GBL) are particularly concerning due to their inherent hazards and toxicity, posing substantial risks to both environmental and human health. Safer alternatives, such as the biomass-derived γ-valerolactone (GVL) solvent, could alleviate such concerns. To evaluate the impact of various perovskite components, particularly the environmental and human health footprint associated with the use of specific solvents, we report a life cycle assessment (LCA) analysis on the synthesis and further processing of prototypical perovskite active layers. The characterization confirmed that GVL can mitigate the footprint of 17.8% and 15.9% compared to GBL and DMF respectively in the synthesis of MAPbI₃, and 23.4% and 18.4% in comparison with GBL and DMF when producing FAPbI₃. Moreover, the study highlights that designing greener, less impactful organic and metal cations is essential for significantly reducing the environmental footprint of MHP layers manufacturing.