In this study, the performance of the AZO/ZnO/CdS/CIGS solar cell configuration was measured by using the AFORS-HET numerical simulation program, which aimed to formulate an optimal design. The numerical simulation of the aforementioned solar cell arrangement demonstrates that it is possible to achieve an efficiency of 9.28% with a thickness of 1μm, this result is consistent with the experimental conclusion (where the efficiency was 9.65% for a thickness of 1μm). Through the use of simulation results, we improved the above-mentioned cell by changing the thickness, concentration, and band gap. It shows that the maximum efficiency (Eff) of this solar cell can reach 17.46% during the optimization for this configuration, which can be obtained at a thickness of 3μm for CIGS layer and at 1.5 AM standard illumination.