Fig. 6

Effect of reducing agents in precursor on Sn–Pb mixed perovskites. a Illustration of solution and crystal structure of Sn–Pb-based perovskite with and without reductant. b Transmittance, XPS, and TRPL decay without and with Sn metallic powder. Reproduced with permission from [17], copyright Springer Nature, 2019. c Schematic diagram of antioxidation and defect passivation with zwitterion FSA. XPS without and with FSA and J-V curve of Sn–Pb mixed PSC with FSA. Reproduced with permission from [18], copyright Springer Nature, 2020