Unlocking the potential of CIGS solar cells: harnessing CZTS as a second absorber layer for enhanced performance and sustainability

Copper Indium Gallium Selenide (CIGS) solar cells represent a highly promising technology for sustainable energy generation. Despite their potential, widespread adoption has been hindered by the inherent toxicity of their constituent materials and concerns about device stability. In this study, we introduce a novel approach to address the toxicity and stability issues and enhance the efficiency of CIGS solar cells. Specifically, we used CuO-SnO₂: F as green buffer layer to replace CdS in our solar cell structure. After that, we employed a dual-absorber layer configuration using CIGS and Copper Zinc Tin Sulfide (CZTS). This strategy allowed us to reduce the thickness of the CIGS layer, thereby diminishing its associated toxicity, while maintaining or improving solar cell performance. Using the Silvaco TCAD simulation tool, we meticulously analyzed the impact of this configuration on solar cell efficiency and other critical parameters. Our results demonstrate a significant increase in efficiency from 15.6 to 18.3% by integrating CZTS as a secondary absorber layer. This study not only highlights the effectiveness of combining CIGS with CZTS but also sets a precedent for future optimization of high-efficiency, environmentally benign solar cells. This advancement contributes meaningfully to the progression of renewable energy technologies and supports the development of more sustainable energy solutions.