Fluorinated isopropanol for improved defect passivation and reproducibility in perovskite solar cells

Abstract

Surface defect passivation is crucial for improving the efficiency and stability of perovskite solar cells. However, its reproducibility and universal applicability have not been fully explored, limiting large-scale production. Here we introduce a passivation strategy based on fluorinated isopropanol for full passivation of surface defects with only a thin layer of low-dimensional perovskite, which does not interfere with charge transport. Fluorinated isopropanol reduces the reactivity of passivator molecules with the perovskite and allows the use of high passivator concentrations, ensuring complete defect passivation. A subsequent rinse with a solvent mixture of fluorinated isopropanol and isopropanol removes the excess passivator molecule. We demonstrate that the strategy has a broad processing window with high tolerance for deviations to the passivator concentration and is applicable to various device architectures, perovskite compositions and device areas. This method results in high power conversion efficiencies and has the potential to improve scalability and production yields in industrial manufacturing.