Back contact is one of the most important components of a solar cell, responsible for collecting charges effectively. If the back contact's metal work function is lower than the ideal value, it creates a Schottky barrier at the interface between the back contact and the absorber layer. This barrier significantly impedes charge collection and results in performance losses by increasing recombination rates and reducing the open-circuit voltage (Voc). To evaluate this effect, the cell was simulated using various back contact materials with differing work functions: Cu (4.65 eV), Ag (4.74 eV), Fe (4.81 eV), C (5.0 eV), Au (5.1 eV), W (5.22 eV), Ni (5.5 eV), Pd (5.6 eV), Pt (5.7 eV), and Se (5.9 eV) . The results indicate that higher work function materials reduce energy barriers at the interface, thereby enhancing charge collection and minimizing recombination losses. Among the materials studied, selenium (Se), with a work function of 5.9 eV, demonstrated the best performance, yielding a Voc of 0.8483 V, a short-circuit current density (Jsc) of 35.604 mA/cm 2 , a fill factor (FF) of 85.67%, and a power conversion efficiency (PCE) of 25.87%.These findings align with previous studies showing that back contacts with higher work functions improve energy alignment at the interface, facilitating better charge transport and reducing losses .