Comparative Performance Analysis Between CIGS Single-Junction and CIGS Tandem Multi-Junction Solar Cell

We present a comparative study between CIGS tandem and CIGS single-junction solar cells. The solar cell parameters like open circuit voltage, short circuit current density, fill factor, maximum power and external quantum efficiency are compared. Calculations use the standard software tool SILVACO ATLAS. We first optimize the structure of the tandem solar cell by varying the thickness of each layer, and then compare the results with the single junction cells. The open circuit voltage of the tandem and single junction cells is almost same, however, the tandem cell is approximately 14% more efficient and it provides 12% more current than the single junction cells.