An effect of band gap engineering, absorber layer type, and Ga/(Ga+In) ratio variation on the performance of CIGS thin-film solar cells

Abstract

Copper Indium Gallium Selenide (CIGS) solar cells represent a promising class of thin-film photovoltaic technologies due to their tunable band gap and compatibility with industrial-scale applications. This study investigates the influence of absorber layer classification, band gap engineering, and the Ga/(Ga+In) compositional ratio on the performance of CIGS solar cells using numerical simulations in Silvaco ATLAS. To maximize the cell efficiency, an Invasive Weed Optimization (IWO) algorithm is employed, capitalizing on its robust global search capability. Simulation outcomes reveal that, with optimal parameter tuning, CIGS solar cells can theoretically attain an efficiency of up to 32.85%, along with a fill factor of 83.2%, open-circuit voltage of 0.63 V, and short-circuit current density of 62.41 mA/cm². These results significantly surpass existing experimental records and emphasize the critical role of absorber layer design and band gap modulation. The findings underscore the effectiveness of computational optimization in photovoltaic device engineering and suggest that further advancements in material design could drive next-generation thin-film solar technologies toward even higher efficiencies.