Performance Analysis of a Cu(In1-xGax)Se2 Solar Cell with Nontoxic WS2 and WSSe Buffer Layers

Significant studies haves been undertaken to improve the power conversion efficiency (PCE) of the Cu(In1-xGax)Se-2 (CIGS) solar cell by varying the energy bandgap of the CIGS layer to match it with the solar spectrum and back surface field effect. In the past, a thin film CIGS solar cell with high PCE was reported with conventional CdS material as a buffer layer, which is a toxic material. In this paper, SCAPS-1D software is used to examine the performance of a single-junction solar cell as CIGS absorber with WS2 and WSSe Janus buffer materials to avoid the toxic effects of CdS material. Optimization of the CIGS energy bandgap is performed by stoichiometric variation of CIGS material composition. The impact of thickness and doping concentration of the CIGS absorber on the solar cell performance is further examined for device structures of n-ZnO:Al/n-WS2/p-CIGS and n-ZnO:Al/n-WSSe/p-CIGS. The study reveals that the WSSe Janus layer is a suitable material for fabrication of the buffer layer in CIGS solar cells. A maximum PCE of 25.81% is obtained for the CIGS solar cell with a WSSe buffer layer. Furthermore, the study analyzes effects of temperature, series/shunt resistance and work function of the metal contacts on the performance parameters of the solar cell. This simulation provides an approach to improve the efficiency of the CIGS solar device while decreasing the raw material consumption.

Automated summary

Significant studies have been conducted to improve the power conversion efficiency of CIGS solar cells by adjusting the energy bandgap and using alternative buffer materials. This paper examines the performance of CIGS solar cells with WS2 and WSSe Janus buffer materials using SCAPS-1D software. The study finds that WSSe Janus layer is a suitable choice for the buffer layer in CIGS solar cells and achieves a maximum efficiency of 25.81%.