Organic–inorganic halide perovskites have rapidly become emerging materials for photovoltaic applications. Strong characterization methods are needed to fully comprehend the chemistry and composition of perovskite solar cells. Understanding the interaction between layers inside a cell and how they react with the environment is important to achieve optimum manufacturing processes, and improve the efficiency of perovskite solar cells. The present work demonstrates the material characterizations of organic–inorganic halide perovskites using (i) one-step deposition, (ii) two-steps deposition, (iii) solvent-to-solvent extraction, and (iv) mixed-cation solution processing. Investigations by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM) have been undertaken to better understand the oxidation of core elements of perovskites, film crystallography, morphology, and stoichiometry when using different deposition techniques of perovskites. Time resolved photoluminescence (TRPL) and photoluminescence (PL) allow us to clearly interpret the lifetime and the bandgap of perovskite material. UV-Vis spectrophotometer results help us to investigate the influence of various deposition techniques on optoelectronic properties of perovskite. Mixed-cation perovskites show the most promising results among the four deposition techniques. The best photovoltaic performance is achieved by a SnO2-based mixed-cation perovskite solar cell with a power conversion efficiency of 18.75%. A power conversion efficiency of 16.74% is obtained by a TiO2-based mixed-cation perovskite solar cell when the optimum thickness of the TiO2 blocking layer is 60–65 nm
