This study introduces zinc salts with organic anions, specifically Zn(OOSCF₃)₂, to improve the performance and stability of perovskite solar cells. Interstitial iodide defects are a major issue in perovskite solar cells, limiting efficiency and stability. These defects can be generated during solution, film, and device processing, accelerating degradation. The addition of Zn(OOSCF₃)₂ in the perovskite solution effectively controls iodide defects by reducing molecular iodine to iodide and precipitating excess iodide through Zn-amine complexes. This results in improved photoluminescence quantum efficiency and reduced deep trap density, despite a slight reduction in grain size. The study demonstrates that Zn(OOSCF₃)₂ enhances the quality and uniformity of perovskite films, enabling the fabrication of large-area perovskite solar minimodules with aperture areas of 78–108 cm². These minimodules achieved power conversion efficiencies of 19.60% and 19.21%, as certified by the National Renewable Energy Laboratory (NREL), making them the highest efficiency for these sizes. The zinc additives also improve the uniformity and reproducibility of perovskite films, facilitating the production of larger aperture area modules. The study also shows that Zn(OOSCF₃)₂ reduces the formation of molecular iodine and iodide interstitials, which are key factors in the degradation of perovskite solar cells. This leads to enhanced device efficiency and stability. The zinc cations and anions work synergistically to passivate defects, reduce non-radiative recombination, and improve the overall performance of the solar cells. The study highlights the importance of controlling iodide interstitials in perovskite solar cells to achieve high-efficiency and stable modules. The results demonstrate that Zn(OOSCF₃)₂ is an effective additive for improving the performance and stability of perovskite solar cells, enabling the production of high-efficiency, large-area modules.This study introduces zinc salts with organic anions, specifically Zn(OOSCF₃)₂, to improve the performance and stability of perovskite solar cells. Interstitial iodide defects are a major issue in perovskite solar cells, limiting efficiency and stability. These defects can be generated during solution, film, and device processing, accelerating degradation. The addition of Zn(OOSCF₃)₂ in the perovskite solution effectively controls iodide defects by reducing molecular iodine to iodide and precipitating excess iodide through Zn-amine complexes. This results in improved photoluminescence quantum efficiency and reduced deep trap density, despite a slight reduction in grain size. The study demonstrates that Zn(OOSCF₃)₂ enhances the quality and uniformity of perovskite films, enabling the fabrication of large-area perovskite solar minimodules with aperture areas of 78–108 cm². These minimodules achieved power conversion efficiencies of 19.60% and 19.21%, as certified by the National Renewable Energy Laboratory (NREL), making them the highest efficiency for these sizes. The zinc additives also improve the uniformity and reproducibility of perovskite films, facilitating the production of larger aperture area modules. The study also shows that Zn(OOSCF₃)₂ reduces the formation of molecular iodine and iodide interstitials, which are key factors in the degradation of perovskite solar cells. This leads to enhanced device efficiency and stability. The zinc cations and anions work synergistically to passivate defects, reduce non-radiative recombination, and improve the overall performance of the solar cells. The study highlights the importance of controlling iodide interstitials in perovskite solar cells to achieve high-efficiency and stable modules. The results demonstrate that Zn(OOSCF₃)₂ is an effective additive for improving the performance and stability of perovskite solar cells, enabling the production of high-efficiency, large-area modules.