All‐inorganic CsPbI3 holds promise for efficient tandem solar cells, but reported fabrication techniques are not transferrable to scalable manufacturing methods. Herein, printable CsPbI3 solar cells are reported, in which the charge transporting layers and photoactive layer are deposited by fast blade‐coating at a low temperature (≤100 °C) in ambient conditions. High‐quality CsPbI3 films are grown via introducing a low concentration of the multifunctional molecular additive Zn(C6F5)2, which reconciles the conflict between air‐flow‐assisted fast drying and low‐quality film including energy misalignment and trap formation. Material analysis reveals a preferential accumulation of the additive close to the perovskite/SnO2 interface and strong chemisorption on the perovskite surface, which leads to the formation of energy gradients and suppressed trap formation within the perovskite film, as well as a 150 meV improvement of the energetic alignment at the perovskite/SnO2 interface. The combined benefits translate into significant enhancement of the power conversion efficiency to 19% for printable solar cells. The devices without encapsulation degrade only by ≈2% after 700 h in air conditions.

All-inorganic halide perovskites hold promise for emerging thin-film photovoltaics due to their excellent thermal stability. Unfortunately, it has been challenging to achieve high-quality thin films over large areas using scalable methods under realistic ambient conditions. Here, we provide important lessons on controlling the solidification and crystallization of CsPbI2Br perovskite inks during ambient scalable fabrication, with results of superior thin-film quality and device performance compared to lab-scale processes.

PbI 2 -EMIMHSO 4 intermediates, finally enlarged the grain size, decreased the trap density, and relaxed the lattice strain of perovskite. The synergetic effects enable us to fabricate ambient blade-coating high-performance CsPbI 3 solar cells with PCEs as high as 20.01% under 1 sun illumination (100 mW cm −2 ) and 37.24% under indoor light illumination (1000 lux, 365 µW cm −2 ); both are the highest for the printed all-inorganic cells for corresponding applications. More importantly, the PCEs of CsPbI 3 -EMIMHSO 4 -based PSCs without any encapsulation retained 95% of the initial PCE value after 1000 h aging under ambient condition. Considering the simplicity and availability of this approach, our study offers an effective materials strategy to passivate crystal defect and regulate interfacial energy alignment for upscaling high-performance and long-term stable PSCs under ambient conditions.Research data are not shared.