Figure 1 shows the surface morphology of perovskites. Perovskite film with different ratios of Cuprous iodide added. Figure 1 (a) ~ (g) are added different Cuprous iodide concentration (a) shows the control device. The perovskite film without added CuI after dropping toluene. The results are consistent with the Jeon et al.9. The perovskite surface very smooth and high- density.