Improved solvent systems for commercially viable perovskite photovoltaic modules.

Commercializing perovskite photovoltaics requires overcoming three critical barriers: the use of toxic solvents in manufacturing, variations in perovskite film quality across large areas, and limited operational reliability. Here, we address these challenges by developing a green solvent–based (γ-valerolactone/2-methyl tetrahydrofuran/dimethylsulfoxide) ink and a solvent-confinement edge-protection strategy, demonstrating large-scale manufacturing of defect-minimized perovskite films under ambient-air conditions. These approaches enabled the production of 7200-square-centimeter perovskite photovoltaic modules that achieved a total-area steady-state efficiency of 17.2% (certified by the National Renewable Energy Laboratory) and that passed all IEC 61215 reliability standards (certified by TÜV Rheinland). This work demonstrates an environmentally responsible path toward commercial manufacturing of perovskite photovoltaics. Editor's summary: A three-component solvent that optimizes ion coordination and evaporation kinetics enables slot-die coating of void-free, high-crystalline perovskite films for solar modules. Wang et al. used a mixture of γ-valerolactone, 2-methyl tetrahydrofuran, and dimethylsulfoxide to replace more hazardous solvents such as N,N-dimethylformamide and added a surfactant to maintain consistent evaporation rates near the film edges. They fabricated stable, 7200-square-centimeter perovskite photovoltaic modules with a certified power conversion efficiency of 17.2%. —Phil Szuromi [ABSTRACT FROM AUTHOR]