Volatile Perovskite Precursor Ink Enables Window Printing of Phase‐Pure FAPbI3 Perovskite Solar Cells and Modules in Ambient Atmosphere

Abstract Despite the great success of perovskite photovoltaics in terms of device efficiency and stability using laboratory‐scale spin‐coating methods, the demand for high‐throughput and cost‐effective solutions remains unresolved and rarely reported because of the complicated nature of perovskite crystallization. In this work, we propose a stable precursor ink design strategy to control the solvent volatilization and perovskite crystallization to enable the wide speed window printing (0.3 to 18.0 m/min) of phase‐pure FAPbI 3 perovskite solar cells (pero‐SCs) in ambient atmosphere. The FAPbI 3 perovskite precursor ink uses volatile acetonitrile (ACN) as the main solvent with DMF and DMSO as coordination additives is beneficial to improve the ink stability, inhibit the coffee rings, and the complicated intermediate FAPbI 3 phases, delivering high‐quality pin‐hole free and phase‐pure FAPbI 3 perovskite films with large‐scale uniformity. Ultimately, small‐area FAPbI 3 pero‐SCs (0.062 cm 2 ) and large‐area modules (15.64 cm 2 ) achieved remarkable efficiencies of 24.32 % and 21.90 %, respectively, whereas the PCE of the devices can be maintained at 23.76 % when the printing speed increases to 18.0 m/min. Specifically, the unencapsulated device exhibits superior operational stability with T 90 >1350 h. This work represents a step towards the scalable, cost‐effective manufacturing of perovskite photovoltaics with both high performance and high throughput.