Validating the “greenness” of chemicals via life cycle assessment: the case of anisole as an anti-solvent in perovskite solar cells†

Abstract

Technological development is increasingly driven by environmental sustainability, with labels like ‘green’ gaining traction. However, the complex interactions in a product's life cycle make the environmental impact of materials and chemicals highly context-dependent, highlighting the need for context-specific environmental assessments. Anisole has been popularly used as a “green” alternative to chlorobenzene for perovskite solar cell (PSC) fabrication. This work validates the technical and environmental performance of anisole in the fabrication of PSCs. PSCs exhibiting conversion efficiencies exceeding 22% can be attained by using anisole as an antisolvent. Moreover, around 50% reduction in the potential toxicity is obtained when substituting chlorobenzene for anisole embodied in the carcinogenic human and ecosystem toxicity impact categories. Nonetheless, anisole embodies higher impact in all 14 remaining impact categories. This is due to anisole's multistep synthesis procedure that contributes to more than double the climate change impact of chlorobenzene, synthesized by a single-step method. To reduce the emissions several recommendations and strategies are proposed. Ultimately, it has been proved that context-specific and transparent environmental assessments are needed to make informed decisions in research and development leading to environmentally sustainable solutions.