Efficient approach for optical and morphological characterization of hybrid perovskite films based on reflectance and transmittance measurements

Abstract Organo-inorganic perovskites (OIPs) have been intensively studied due to their potential application in low-cost, high-efficiency energy conversion in solar cells. Despite the great improvement in the quality of OIP films, wide dispersion in the same batch of perovskite-based devices remains an obstacle to obtaining highly reproducible results. For that reason, new and efficient strategies for testing deposition results is essential. Here we present a simple and efficient procedure for characterizing optical and morphological properties based on simultaneous reflectance and transmittance measurements under normal incidence over a methylammonium lead iodide film. The proposed method provides qualitative and quantitative morphological information associated with the film roughness as well as information about the position of the optical gap and possible contributions to optical dispersion in the structure that can be used as a simple diagnostic tool to optimize film deposition. Results are compared and validated with electronic and atomic force microscopy, as well as first-principles calculations.