Abstarct: This dissertation discussed the fabrication and characterization of perovskite solar cells baxsed on zinc oxide nanoparticles (ZnO-NP). This study aimed to investigate the ruleof ZnO blocking laxyer and to study its photovoltaic properties as a charge transfer medium in a perovskite solar cell. In this study, ZnO nanoparticles was synthesized by the sol-gel method, after that ZnO-NP cell solution was prepared and laxyered by the spin coathing method. X-ray diffraction (XRD), infrared (FT-IR) spectroscopy, photoluminescence (PL), and diffraction reflectance (UV–Vis) measurements have been used to characterize the structureal and optical properties of these nanoparticles. Also, the solar cell parameters were investigated by tracing of the current-voltage (I-V) analysis. The modified photovoltaic performance was observed in the presence of the ZnO blocking laxyer.