Controllable Cosolvent Blade-Coating Strategy toward Low-Temperature Fabrication of Perovskite Solar Cells

Organic–inorganic hybrid perovskite solar cells (PSCs) have exhibited great progress in recent years, although it still remains challenging to translate them from the lab to the fab for commercialization. Further process simplification and design of stable ink formulations are required to ensure fine control over the perovskite film quality for scalable coating. In this work, a facile and controllable room-temperature fabrication of high-performance bladed PSCs in air is proposed by directly introducing the green solvent methylammonium acetate (MAAc) into low-toxicity 2-methoxyethanol (2-Me). This combination could better control the formation process of perovskite by forming the perovskite-like intermediate phase with PbI2 in its unique ionic network so as to facilitate the film uniformity and the process reproducibility; meanwhile, the high volatility of 2-Me still enables the low-temperature fabrication. Consequently, with the assistance of a benzohydrazide (BZH) passivator, the target device achieves a champion PCE of 20.11% and a superior fill factor of 82.8% in inverted MAPbI3-based devices, along with significant device stability. Herein, the strategy provides a feasible prospect for scalable coating to fabricating high-performance PSCs with high reproducibility and controllability under ambient conditions.