Method for fabricating flexible solar cell perovskite semiconductors via a sheet of paper applicator soaked in anti-solvent

Most perovskite films in laboratories are deposited by spin coating and antisolvent engineering to achieve high efficiency. Industry prefers roll-to-roll compatible techniques such as slot-die or blade coating, where the application of anti-solvent has always proven to be problematic. We show a novel method that uses a sheet of paper to deposit the perovskite films in air. Soaking the paper used as an applicator in a green anti-solvent improved the efficiency of the solar cell by 82% compared to the same when using a sheet of dry paper. Finally, an automated version of the method is proposed for future implementation.