A universal co-solvent dilution strategy enables facile and cost-effective fabrication of perovskite photovoltaics

Cost management and toxic waste generation are two key issues that must be addressed before the commercialization of perovskite optoelectronic devices. We report a groundbreaking strategy for eco-friendly and cost-effective fabrication of highly efficient perovskite solar cells. This strategy involves the usage of a high volatility co-solvent, which dilutes perovskite precursors to a lower concentration (<0.5M) while retaining similar film quality and device performance as a high concentration (>1.4M) solution. More than 70% of toxic waste and material cost can be reduced. Mechanistic insights reveal ultra-rapid evaporation of the co-solvent together with beneficial alteration of the precursor colloidal chemistry upon dilution with co-solvent, which in-situ studies and theoretical simulations confirm. The co-solvent tuned precursor colloidal properties also contribute to the enhancement of the stability of precursor solution, which extends its processing window thus minimizing the waste. This strategy is universally successful across different perovskite compositions, and scales from small devices to large-scale modules using industrial spin-coating, potentially easing the lab-to-fab translation of perovskite technologies. A universal strategy is reported for formation of very low concentration of perovskite precursor inks that yields high-efficiency photovoltaics while substantially reducing toxic waste generation, fabrication cost and process complexity, thus taking a step closer towards commercialization.

Automated summary

This article introduces an eco-friendly and cost-effective strategy for fabricating high-efficiency perovskite solar cells, which involves diluting perovskite precursors with a high volatility co-solvent to reduce toxic waste and material cost. The strategy is universally successful across different perovskite compositions, potentially facilitating the translation of perovskite technologies from lab to fab.