Yinke Wang

Abstract Environmentally sensitive ammonium halides have emerged as indispensable surface passivators for perovskite solar cells, demonstrating broadly effective performance at the laboratory scale1-4. However, the sensitivity of ammonium halides to humidity typically necessitates operation under an inert atmosphere5.

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.