This study focuses on optimization of solar cells using antimony selenide (Sb2Se3) as absorber layer. A novel solar cell structure, designed and simulated with configuration ZnO/i-ZnO/Sb2Se3/NiO or SnS, demonstrates a notable efficiency improvement. The performance of this solar cell was rigorously evaluated using the SCAPS simulation tool. Key structural parameters were optimized as follows: ZnO at 30 nm, i-ZnO at 20 nm, Sb2Se3 as active layer at 100 nm, and NiO at 20 nm. NiO & SnS, utilized as a back surface field (BSF), effectively minimizes recombination. Various parameters were analyzed, including the band diagram, thickness, bandgap, doping concentration, effect of concentration on electric field, recombination and generation rates, temperature effects, and series and shunt resistance of proposed structure. The proposed model achieved an efficiency of up to 31.4%, highlighting the potential of NiO & SnS as BSF in antimony selenide solar cells. The metal work functions for front and back contacts are 4.4 eV and 5.1 eV respectively. This breakthrough suggests a transformative path toward significantly enhanced solar cell performance, showcasing the latent potential of NiO BSF in optimizing Sb2Se3-based solar cells.