In order to make ZnO-based dye-sensitized solar cells that act as photosensitizers for Terminalia catappa fruit, the metal oxide semiconductor of undoped and Ni-doped ZnO nanoparticles was synthesized using the solvothermal method. Ethanol was used as the solvent. The X-ray Diffraction, Field Emission-Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, Ultraviolet-Visible, and Electrochemical Impedance Spectroscopy for structural, optical, and electrical characterizations were used to analyze these produced nanoparticles. Additionally, a solar simulator with one sun AM 1.5G (100 mW/cm²) light supplied by a 300 W xenon lamp was used to analyze the J-V characterization of solar cell parameters. This result also shows that the corresponding efficiency of a solar cell application can be increased by incorporating Ni into ZnO nanoparticles in a solution.