High-efficiency CIGS solar cell by optimization of doping concentration, thickness and energy band gap

Abstract

In this paper, the performance of copper-indium-gallium-diselenide Cu(In,Ga)Se2 solar cell, with ZnO window layer, ZnSe buffer layer, CIGS absorber layer and InGaP reflector layer was studied. The study was performed using the TCAD Silvaco simulator. The effects of grading the band gap of CIGS absorber layer, the various thicknesses and doping concentrations of different layers have been investigated. By optimizing the solar cell structure, we have obtained a maximum open circuit voltage of 0.91901 V, a short circuit current density of 39.89910 mA/cm2, a fill factor (FF) of 86.67040% and an efficiency of 31.78% which is much higher than the values for similar CIGS solar cells reported so far.