Influence of Cu/In loading ratio in grain size of the CuInS2 films for CuInS2-based solar cells

The attainment of Net Zero Emissions (NZE) by 2050 has become a globally acknowledged goal, and solar photovoltaic (PV) power generation stands out as one of the most promising approaches towards achieving the net zero CO2 emissions objective. In this treatise, we present the fabrication and characterization of CuInS2 thin-film solar cells, wherein the composition and structure of CuInS2 layers were prepared through the process of sulfurization of Cu-In precursors. Another research endeavor was dedicated to examining the correlation between cell performance and CuInS2 grain size, which is directly determined by the precursor Cu/In ratio. Our findings reveal that augmenting the precursor Cu/In ratio from 0.75 to 0.82 produced a surge in current density, escalating from 3.39 mA/cm$^{2}$ to a value surpassing 6 mA/cm$^{2}$. Furthermore, we obtained numerous measured parameters that evinced a higher precursor Cu/In ratio to possess the potential to enhance the efficiency of the solar cell. These findings hold immense significance as they suggest the viability of increased efficiency in solar cell performance.