Rationally Designed Eco‐Friendly Solvent System for High‐Performance, Large‐Area Perovskite Solar Cells and Modules

The important but remained issue to be addressed to achieve the mass production of perovskite solar modules include a large‐area fabrication of high‐quality perovskite film with eco‐friendly, viable production methods. Although several efforts are made to achieve large‐area fabrication of perovskite, the development of eco‐friendly solvent system, which is precisely designed to be fit to scale‐up methods are still challenging. Herein, this work develops the eco‐friendly solvent/co‐solvent system to produce a high‐quality perovskite layer with a bathing in eco‐friendly antisolvent. The new co‐solvent/additive, methylsulfonylmethane (MSM), efficiently improves the overall solubility and has a suitable binding strength to the perovskite precursor, resulting in a high‐quality perovskite film with antisolvent bathing method in large area. The resultant perovskite solar cells showed high power conversion efficiency of over 24% (in reverse scan), with a good long‐term stability under continuous light illumination or damp‐heat condition. MSM is also beneficial to produce a perovskite layer at low‐temperature or high‐humidity. MSM‐based solvent system is finally applied to large‐area, resulting in highly efficiency perovskite solar modules with PCE of 19.9% (by aperture) or 21.2% (by active area) in reverse scan. These findings contribute to step forward to a mass production of perovskite solar modules with eco‐friendly way.