Characterization of methylammonium lead iodide perovskite solar cells by surface morphology changes

Organic-inorganic halide Perovskite solar cells have extremely high power conversion efficiencies of 22.1%, as officially recognized by the US National Renewable Energy Laboratory (NREL). These solar cells are therefore attractive candidates for use in next generation photovoltaic applications. Perovskite materials for incorporation into solar cells are prepared by a two-step solution fabrication process to generate polycrystalline structures with diverse grain sizes. PbI₂ is the main material used in the synthesis of organic-inorganic hybrid perovskite, particularly when the sequential deposition method is employed, as it facilitates the formation of a well-organized perovskite layer. To improve the performance of these devices, the properties of PbI₂ properties need to be investigated. We therefore examined the effects of PbI₂ concentration in mesoporous perovskite solar cells prepared using a two-step solution deposition method. Samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis spectrometry, and atomic force microscopy (AFM). The results of this work confirm the importance of the PbI₂ layer in high efficiency perovskite solar cells.