Methylammonium Chloride Additive in Lead Iodide Optimizing the Crystallization Process for Efficient Perovskite Solar Cells

Figure 2

The surface SEM images of perovskite films added different concentrations of MACl: (a) without MACl; (b) with 2 g/L MACl; (c) with 5 g/L MACl; (d) with 10 g/L MACl (scale: 2 μm).

(a)

(b)

(c)

(d)