The increasing depletion of fossil fuels and the escalation of global temperatures have intensified the need for sustainable energy sources such as solar power. Copper Zinc Sulphide (CuZnS) is a potential absorber for solar cells. This study reports the structure and composition of annealed CuZnS samples using X-ray Photoelectron Spectroscopy (XPS) analysis technique. CuZnS thin films prepared using low-cost chemical bath deposition (CBD) technique are annealed at 100°C, 200°C, and 300°C. The samples are analysed using Energy Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), UV Visible NIR spectroscopy (UV-VIS) and Hall effect measurements. XPS and EDX analyses confirmed an increase in zinc content with annealing, accompanied by a decrease in sulphur concentration and a reduced Cu/Zn ratio. Electrical measurements (Hall measurements) revealed an increase in conductivity from 2.311 × 10−6 Ω−1·cm−1 to 7.403 × 10−6 Ω−1·cm−1. Optical characterisation (UV-VIS) indicated a tunable bandgap ranging from 2.50 eV to 2.73 eV, suitable for photovoltaic applications. Structural analysis (XRD) demonstrated improved crystallinity and phase purity upon annealing. SEM images showed an increase in grain size from 149 nm to 178 nm, suggesting enhanced film quality. Overall, the results highlight that annealed CuZnS thin films exhibit improved optoelectronic and structural characteristics, making them promising candidates for cost-effective solar absorber layers in photovoltaic devices.
C. et al. (Thu,) studied this question.