Copper Zinc Tin Sulfide (CZTS) solar cells have absorbed significant appeal as an efficient approach for sustainable photovoltaic technology. This research introduces a groundbreaking approach to thin-film solar cells using a novel Fluorine-doped CZTS composition with a new device configuration. The DFT calculations indicate that F atoms prefer Cu sites and maintain a direct band gap in CZTS, promoting n-type conductivity. Optical studies demonstrate that F-doping enhances conductivity, refractive index, and light absorption through the visible spectrum. Furthermore, the performance of CZTS-based cells in both heterojunction and homojunction configurations is under investigation. The homojunction configuration with Al:ZnO intermediate layer enhances V