A novel design of double junction CZTS/CdS solar cell with transparent intermediate layer

In this paper, a novel double junction CZTS/CdS solar cell is proposed, where Copper Zinc Tin Sulfide (CZTS) and Cadmium Sulfide (CdS) are applied as top and bottom cells. Zinc Telluride (ZnTe) and Zinc Selenide (ZnSe) are used as Anti-Reflection Coating (ARC) layers in order to decrease the reflection of solar radiant beams. Zinc Oxide (ZnO) layer is used between the top cell and the bottom cell as a transparent intermediate layer which increases the current flow. Current density matching was established between short-circuit current densities in top cell and bottom, and the short-circuit current density of 22.2 mA/cm(2) was reached in the solar cell. The maximum power conversion efficiency of 48.05% and maximum fill factor of 84.56% was obtained by optimizing double junction CZTS/CdS solar cell with changing the thickness of CZTS and CdS layers and doping concentration of each solar cell layer.