<p>Perovskite thin-film solar cells have garnered significant attention due to their potential for high efficiency as emerging energy sources. In this study, the incorporation of cubic nanoclusters into a CH₃NH₃PbI₃ perovskite solar cell with a 250-nm absorber layer was investigated to enhance its optical performance. The presence of nanoclusters improves the absorption spectrum and optical current density by intensifying the local electric fields. Utilizing nanoparticles in a clustered configuration and optimizing their structure and spacing can enhance the overall efficiency of solar cells primarily through light scattering and localized surface plasmon resonance (LSPR). The finite-difference time-domain (FDTD) method was employed to analyze the electric field distribution, absorption spectrum, and optical current density in these structures. Key parameters studied include the material composition (Au, Ag, Al, and Cu), dimensions, spatial placement within the cell, geometric arrangement (two distinct configurations), and interparticle spacing of the cubic nanoclusters in the absorber layer. Among the proposed designs, Al nanoclusters placed in the lower surface and middle of the perovskite layer in the first geometry yielded the best photocurrent densities of 20.65 mA/cm² (an 18.47% improvement) and 21.56 mA/cm² (a 23.70% improvement), respectively. For the second geometry, these values were 20.02 mA/cm² (a 14.86% improvement) and 21.49 mA/cm² (a 23.30% improvement). For comparison, the reference cell demonstrated an optical current density of 17.43 mA/cm². Furthermore, the best-performing structure achieved an open-circuit voltage of 1.002 V, a fill factor of 0.88, and a power conversion efficiency (PCE) of 19.11%. These findings present a significant opportunity for future research and pave the way for the creation of more efficient, thinner, and affordable cells.</p>