ZnO doping profile effect on CIGS solar cells efficiency and parasitic resistive losses based on cells equivalent circuit

The window layer of the CIGS thin film solar cells plays the role of transparent front contact and the n-side of pn-heterojunction. Thus the variation of window layers electrical and optical properties can affect the cell performance. Properties of Al-doped Zinc oxide (ZnO) thin film as most common used window layer for CIGS solar cells were studied via simulation using the simulation program called SCAPS-1D. This study is aimed to find the effect of ZnO layer doping profile on cell performance. It is found that increasing Al-content up to 5% in ZnO layer will lead to increasing the cell efficiency and will decrease the cell series and shunt resistance.