A Wenzel Interfaces Design for Homogeneous Solute Distribution Obtains Efficient and Stable Perovskite Solar Cells

Abstract The coffee‐ring effect, caused by uneven deposition of colloidal particles in perovskite precursor solutions, leads to poor uniformity in perovskite films prepared through large‐area printing. In this work, the surface of SnO 2 is roughened to construct a Wenzel model, successfully achieving a super‐hydrophilic interface. This modification significantly accelerates the spreading of the perovskite precursor solution, reducing the response delay time of perovskite colloidal particles during the printing process. Additionally, the micro‐spherical depression structure on the SnO 2 surface effectively inhibits the migration of colloidal particles toward the edges of liquid film, trapping perovskite colloidal particles at the buried interfaces and improving film uniformity. Due to the synergistic effect of super‐hydrophilicity and micro‐rough structure on the surface of SnO 2 , leading to a substantial improvement in the quality of perovskite crystals. Therefore, the efficiency of printing prepared flexible devices (0.101 cm 2 ) reached 25.42% (certified 25.12%). Moreover, the efficiency of rigid and flexible large‐scale perovskite solar modules (PSMs) based on meniscus‐coating manufacture reached 21.34% and 16.99% (100 cm 2 ), respectively, and demonstrated superior environmental stability by maintaining an initial efficiency of 91% after being stored in atmospheric conditions for 2000 h, offering practical guidance for fabricating high‐performance and stable large‐scale perovskite solar cells (PSCs).