Performance analysis of ultra-thin CIGS solar cells with ZnS/CdS/ZnSe buffer layers

This paper presents a modeling study of an ultra-thin CIGS-based solar cell with a 0.5-micron-thick absorber layer, using Silvaco Atlas software. The CIGS solar cell module incorporates three buffer layers made of ZnS, CdS, and ZnSe. Notably, our study distinguishes itself by utilizing an ultra-thin 0.5-micron absorber layer, a substantial departure from the conventional 2-micron absorber layer typically employed in CIGS-based solar cells. We investigate the impact of layer thickness, doping variations, and temperature changes on module performance by using three different buffer layers composing of ZnS, CdS and ZnSe. The window layer, absorber layer, and contacts remain constant throughout the study. In order to make the proposed module more realistic, defect parameters were also incorporated for each layer. Key parameters such as efficiency, fill factor, open-circuit voltage, and short-circuit current density are extracted through simulation. We compare these parameters among different buffer layer modules to assess how layer thickness, doping concentration, and temperature affect the performance of CIGS-based solar cells. Optimal values for the ZnS, CdS, and ZnSe modules obtained from the simulation are subsequently employed to enhance each module. The JV curve and quantum efficiency of the enhanced modules are also extracted for comparison. Our research seeks to enhance the efficiency and lower the expenses associated with CIGS solar cells by diminishing absorber thickness and employing environmentally friendly buffer layer materials. The findings of this investigation may serve as a roadmap for enhancing scalability and achieving cost-effectiveness in CIGS-based solar cell production in the foreseeable future.