Abstract: In this paper, we have tried to show the importance of doping and defects charged on CIGS solar cells. Indeed according to our simulations, we could see that the electrical performance of these types of cells highly dependent on these two parameters. We also studied the dependence between doping and charged defects on the evolution of the electrical parameters. It was found that the results with neutral defects different from those charged with defects. The doping level for best performance (solar cell with Cu-poor absorber) is lowest with neutral defects than with the charged defects.