Improved performance in bilayer-CIGS solar cell

One of the biggest challenges in using thin film solar cell is reducing manufacturing cost. The reduction of absorber thickness can decrease costs at the expense of reduction cell efficiency. In this study a single junction CuIn_1-xGa_xS₂ (CIGS) solar cells has been simulated with an emphasis on identifying the effect of adding a second CIGS layer on the performance of the cell. To evaluate this, we have simulated the cell using bilayer CIGS (1.15 and 1.28 eV) and compared it with the cell with one absorber layer of 1.15 eV. While the best performance of CIGS cell is for absorber thickness beyond 2.5 μm, our simulation results suggest that the adding of a second CIGS layer with different bandgap can reduce this thickness to less than 1 μm.