[en] Perovskite solar cells have been heavily investigated due to their unique properties such as high power conversion efficiency (PCE), low-cost fabrication by solution processes, high diffusion length, large absorption coefficient, and direct and tunable band gap. PCE of perovskite devices is strongly dependent on the absorber layer properties such as morphology, crystallinity, and compactness, which are required to be optimized. In this work, the CH₃NH₃PbI₃ (170–480 nm) absorber layers with various methylammonium iodine (MAI) concentrations (7, 10, 20 and 40 mg ml⁻¹) and perovskite solar cells with the fluorine-doped tin oxide (400 nm)/C-TiO₂ (30 nm)/Meso-TiO₂ (400 nm)/CH₃NH₃PbI₃ (170–480 nm)/P3HT (30 nm)/Au (100 nm) structure were fabricated. A two-step solution process was used for deposition of the CH₃NH₃PbI₃ absorber layers. The morphology, crystal structure, and optical properties of the perovskite layer grown on glass and also the photovoltaic properties of the fabricated solar cells were studied. The results obtained showed that by controlling the deposition conditions, due to the reduction in charge recombination, PCE enhancement of the perovskite solar cell (up to 11.6%) was accessible. (paper)