Band gap and thickness optimization for improvement of CIGS/CIGS tandem solar cells using Silvaco software.

In this study, we investigated numerical simulations of the double junction solar cells based copper indium gallium diselenide (CIGS/CIGS) using the two-dimensional device simulator Silvaco-Atlas under standard AM1.5G Illumination. We considered the CIGS absorbing layer thickness and its bandgap of sub-cells as key parameters to optimize the performance of the CIGS/CIGS tandem solar cell. The electrical parameters of the best CIGS/CIGS tandem solar cell configuration were a short circuit current density (Jsc) of 18.82mA/cm², an open-circuit voltage (Voc) of 1.84V, a fill factor (FF) of 82.54 %, and the conversion efficiency (η) of 27.03 %. The optimal CIGS absorbing layer thickness of the top and bottom cells corresponding to maximum conversion efficiency obtained were 0.18μm and 3.2μm, respectively, while the optimal band gaps were 1.68eV for top cell and 1.13eV for the bottom cell. These results can be used as a basis for effectively developing low-cost and high-efficiency solar cells. [ABSTRACT FROM AUTHOR]