**4. Results and discussion**

## **4.1 Optimal value of ZnS electronic affinity**

Considering the electrical susceptibility of Zinc Sulfide (*χe*), within the range of 3.9 [31] and 4.5 [32], we investigate the effects of his value on the performance of our modeled device. Observations are mainly carried out on Fill Factor (FF) and Efficiency (*η*) and for a thickness of the absorber layer of 0.5 μm. The results obtained are plotted in **Figure 2** above.

It shows that the optimum value of the ZnS electrical susceptibility for recording the best performance of our solar cell is defined for *χ<sup>e</sup>* ½ � 4*:*1; 4*:*5*eV :* This result is in very good agreement with those reported in literature [17, 19]. The maximum of the parameters is obtained for *χ<sup>e</sup>* ¼ 4*:*3*eV*. This value can be registered as the optimum value of the electrical susceptibility of ZnS for this structure of solar cell.
