Exploring novel Na4XS (X = Se, Te) materials for UV protection and photovoltaic efficiency: First-principles approach

Novel chalcogenide materials exhibit remarkable thermal stability along with regulating optoelectronic properties. The structural, optoelectronic, and transport properties of Na₄XS (X = Se, Te) materials were investigated using the most advanced density function theory. The calculated cohesive and formation energies confirm the stable nature of the studied materials. The study of their band structure profile reveals that their materials have a direct band gap and exhibit characteristics of a semiconducting nature. The determined peaks in the materials’ computed reflectance spectra suggest that they have the potential to be UV-reflective materials. This could lead to their potential use in UV-shielding devices. The negative Seebeck coefficients of the studied materials specify that they possess an n-type conductivity nature. Based on their direct energy gap, stable structure, adjustable optoelectronic performance, and remarkable thermal nature, they have significant potential for a wide range of novel and advanced technological applications.