Sustainable Recycling of Perovskite Solar Cells: Green Solvent-Based Recovery of ITO Substrates

Abstract

Perovskite solar cells (PSCs) emerge as a leading next-generation photovoltaic (PV) technology, with power conversion efficiencies (PCEs) reaching 26.7% for single cells and 36.1% for hybrid tandem cells. As commercialization progresses, the inverted (p–i–n) structure of PSCs gains attention due to its enhanced thermal stability, lower moisture sensitivity, and reduced processing temperatures compared to the conventional (n–i–p) structure. However, sustainability concerns, particularly regarding production costs and end-of-life disposal, become increasingly critical. Recycling PSCs provides a viable solution to these challenges by recovering valuable indium tin oxide (ITO) substrates, which significantly impact material costs. Existing recycling methods for conventional PSCs often use toxic solvents like chlorobenzene (CB) and N,N-dimethylformamide (DMF), posing environmental and health risks. This study introduces an eco-friendly recycling process for ITO-based inverted PSCs using acetone as a green solvent. The results show that recycled ITO substrates maintain their physical, electrical, and optical properties without significant degradation in PSC performance, even after multiple recycling cycles. This green solvent-based approach not only preserves device efficiency but also supports future environmental regulations, highlighting its potential in promoting sustainable and cost-effective PV technologies.