Effects of sulfur incorporation into absorbers of CIGS solar cells studied by numerical analysis

The performance of Cu(In, Ga)Se₂ (CIGS) solar cells with the incorporation of sulfur into the surface region of the absorbers has been studied by numerical simulation. The impacts of sulfur contents and thickness of sulfurized layers in the surface region of absorbers on the performance were evaluated. The results show that the incorporation of sulfur in the CIGS films enhances the open-circuit voltage (V_OC), but concurrently leads to the reduction in short-circuit current density (J_SC). The S/(S+Se) ratios of below 0.2 could improve the cell performance for all thickness of sulfurized layers in this study. For S/(S+Se) ratios of 0.1-0.5, the thickness of 200nm was suggested to enhance the efficiency of devices.