Orientated crystallization of FA-based perovskite via hydrogen-bonded polymer network for efficient and stable solar cells

Formamidinum lead iodide perovskite solar cells commonly suffer from photoinduced phase segregation and humidity instability. Here, the authors design a multifunctional fluorinated additive to promote orientated crystallization of α-phase, and achieve maximum efficiency of 24.1% and T95 over 1000 h.