Revealing the role of tin fluoride additive in narrow bandgap Pb-Sn perovskites for highly efficient flexible all-perovskite tandem cells

Johnpaul K. Pious, Yannick Zwirner, Huagui Lai +11

Tin fluoride (SnF2) is an indispensable additive for high-efficiency Pb-Sn perovskite solar cells (PSCs). However, the spatial distribution of SnF2 in the perovskite absorber is se…