Topography of perovskite surface by atomic force microscopy

The samples we investigated were layers of perovskite CH₃NH₃PbI₃, which were prepared by applying a 3:1 solution of CH₃NH₃I and PbI₂ precursors to glass plates, followed by heating the plates to 120 grad C under a nitrogen atmosphere. The surface of some plates was plasma treated. The resulting surface scans have shown that perovskite forms spherical formations grouped into clusters and that the layers prepared on the plasma plates have greater homogeneity than the layers on the non-plasma plates. The roughness of these surfaces was determined to be 81 nm for the non-plasma surface and 19 nm for the plasma surface. The results have shown that the perch occurrences prepared on the plasma are more promising for solar cells. (authors)