Motivated by the growing interest in efficient materials for renewable energy technologies, this work aims to investigate the fundamental properties of CdX \(_2\) (X = S and Te) binary chalcogenides for potential optoelectronic applications. We present a comprehensive analysis of the structural, electronic, and optical properties of CdX \(_2\) through ab initio calculations. The electron exchange-correlation effects are accurately described using the Generalized Gradient Approximation and the modified Becke–Johnson methods. The structural properties, supported by computed formation energies, confirm the thermodynamic stability and feasibility of the materials under investigation. The optimized CdX \(_2\) (X = Te, S) structures exhibit direct band gaps of 2.21 eV and 1.17 eV, respectively, indicating semiconducting behavior. In addition, the optical properties reveal strong absorption and elevated conductivity in the ultraviolet range, along with the ability to absorb visible light. Furthermore, the calculated dielectric constants reach maximum values of 13.49 for CdTe \(_2\) at 2.76 eV and 9.34 for CdS \(_2\) at 4.77 eV, demonstrating a significant light–matter interaction and supporting the suitability of these compounds for future energy-efficient optoelectronic devices.
