Suppression of Sn2+oxidation and formation of large-size crystal grains with multifunctional chloride salt for perovskite solar cell applications

The C 6 H 8 N 2 O 2 ·2HCl additive is first doped into an FA 0.75 MA 0.25 SnI 3 precursor and plays a positive role in suppressing the generation of Sn 4+ and promoting the formation of large-size crystal grains in FA 0.75 MA 0.25 SnI 3 perovskite films.