The study also explored the impact of the back contact material and series resistance on device performance. Selenium (Se), with a high work function of 5.9 eV, reduced energy barriers, achieving a peak PCE of 25.87%, while minimizing series resistance to 1 Ω improved charge flow, leading to a final efficiency of 24.71%. Temperature effects revealed that the cell performed optimally up to 325 K, after which efficiency declined due to increased carrier recombination. Quantum efficiency significantly improved from an initial 87% to 99.13%, maintaining high performance across a wide wavelength range. Importantly, the V2O5-based structure demonstrated the lowest cost (€13.143 for HTM and back contact) compared to other designs, underscoring its commercial viability.