Suppressing interfacial nucleation competition through supersaturation regulation for enhanced perovskite film quality and scalability.

The growing interest in cost-effective and high-performing perovskite solar cells (PSCs) has driven extensive research. However, the challenge lies in upscaling PSCs while maintaining high performance. This study focuses on achieving uniform and compact perovskite films without pinholes and interfacial voids during upscaling from small PSCs to large-area modules. Competition in nucleation at concavities with various angles on rough-textured substrates during the gas-pumping drying process, coupled with different drying rates across the expansive film, aggravates these issues. Consequently, substrate roughness notably influences the deposition window of compact large-area perovskite films. We propose a supersaturation regulation approach aimed at achieving compact deposition of high-quality perovskite films over large areas. This involves introducing a rapid drying strategy to induce a high-supersaturation state, thereby equalizing nucleation across diverse concavities. This breakthrough enables the production of perovskite photovoltaics with high efficiencies of 25.58, 21.86, and 20.62% with aperture areas of 0.06, 29, and 1160 square centimeters, respectively.