The escalating environmental and resource challenges have catalyzed the quest for clean and efficient energy sources. Recent strides in nanomaterial integration have revolutionized electronic devices, propelling breakthroughs in diverse sectors such as chemical sensing, healthcare, agriculture, and renewable energy. While lead (Pb)-based materials have historically dominated high-efficiency solar cells, concerns regarding stability, toxicity, and environmental impact have redirected research efforts toward environmentally friendly Pb-free alternatives. Concurrently, copper indium gallium selenide (CIGS)-based devices rose as an eco-friendly solar cell option because of their non-toxicity, simplicity in fabrication, and enduring stability. This study investigates the feasibility of globally sustainable, inorganic, lead-free photovoltaic cell utilizing CIGS as the absorber layer, molybdenum disulfide (MoS2) as the hole transport layer (HTL), and zinc oxide (ZnO) as the electron transport layer (ETL). Through meticulous optimization of various parameters including absorber layer thickness, doping concentration, and defect density, as well as the properties of the HTL and ETL, the proposed configuration (FTO/ZnO/CIGS/MoS2/Au) achieves exceptional performance metrics. With a fill factor (FF) of 82.35%, an open circuit potential (VOC) of 0.91 V, a short-circuit current (JSC) of 34.86 mA/cm2, and a power conversion efficiency (PCE) of 26.14%, this study marks a significant advancement in photovoltaic cell technology, demonstrating the promise of lead-free materials in sustainable energy generation.