Figure 2

Prepared SFP suspension (a), deposited SFP on the TiO2 at different spray passes (b), conventional one step spin coating of perovskite (route 1) and deposited SFP on CuI at spray passes of 20 (route 2) (c) and XRD patterns of bare CuI and CuI/SFP layers (d), schematic of synthesizing and deposition process of SFP layer (e) and size distribution of the perovskite particles before and after ball milling for 6 hours at 250 rpm monitored by DLS with the number averaged (f).