Meniscus-modulated blade coating enables high-quality α-phase formamidinium lead triiodide crystals and efficient perovskite minimodules

Meniscus coating technique is extensively employed for fabricating large-area perovskite films. Based on this technique, there are still challenges of formamidinium lead triiodide (FAPbI 3 ) nucleation and crystallization in the film-forming process, which significantly hinders the device performance of perovskite solar cell (PSC) modules. Here, we developed a kind of meniscus-modulated blade coating method combined with solvent engineering to realize scalable, high-quality α-phase FAPbI 3 films with larger grain sizes, preferred crystal orientation, excellent uniformity, and controllable thickness. On this basis, a notable 25.31% power conversion efficiency (PCE) for small-area cells (0.09 cm 2 ) and 23.34% PCE for minimodules (aperture area: 12.4 cm 2 ) with a certified PCE of 23.09% have been achieved. Besides, this minimodule exhibited exceptional device stabilities by remaining above 93% of the initial value after 2,000 h outdoor aging testing. This work provides a very promising meniscus coating fabrication method to realize high-performance FAPbI 3 perovskite solar cells and photovoltaic modules.