In this study, un-doped and yttrium-doped copper oxide (Y-doped CuO) samples were produced on glass using the spin coating technique. X-ray diffraction (XRD) patterns for the un-doped and Y-doped CuO demonstrated that all samples have a monoclinic polycrystalline structure, with two maximum peaks (−111)/(002) and (111). The crystallite parameters of the maximum peaks were changed with Y dopant content. Scanning electron microscopy images verified the presence of small aggregated particles on the film’s surfaces. It was observed that charge carrier concentration increased and mobility decreased in CuO thin film with increasing Y concentration. Ultraviolet–visible (UV–Vis) spectrophotometry measurements of the CuO samples revealed average transmittance of 30–40% in the visible region. It was also observed that the energy bandwidth decreased slightly with increasing Y concentration. In this study, the solar cell based on Y-doped CuO semiconductor with the most advanced crystal structure and lowest bandgap was modeled, using SCAPS-1D simulation software. The VOC, JSC, FF, and η values of the Y-doped CuO thin-film solar cell, whose production is sparsely reported in the literature, were calculated based on several physical parameters including interface defect density, electron affinity, work function of the back contact, and operating temperature, and its possible photovoltaic (PV) performance was determined. Depending on the change of these parameters, an improvement or deterioration in the performance of the solar cell was observed. The obtained data were then interpreted and expressed in detail according to the working principles of the solar cell. Thus, this study will allow doped CuO thin-film solar cell production studies to proceed with appropriate and safe steps.