First-Principles study of the electronic Structure, Optical, and thermoelectric properties of novel WSeX (X=S, = S, Te) Chalcogenides: For energy harvesting application

Excellent thermal stability and tunable optoelectronic features are two unique characteristics of ternary chalcogenides. The first-principles investigations were carried out to look into the intricate interactions between the optical, thermoelectric, and electronic features of novel ternary chalcogenides. The stability of these studied materials was confirmed by the computed formation energy values. There is a strong correlation between the formation energy and the ionicity of W-X bonds, indicating that materials with lower formation energy are connected to a higher number of ionic bonds. The valence band maximum and conduction band minimum of both WSeS and WSeTe materials are located at the Gamma- point, which confirms they are direct band gap semiconductors. The heavier element Te is incorporated, making the electronic structure of WSeTe more complex than that of WSeS. The epsilon 1(omega) 1 (omega) was negative at higher photon energy, which is associated with these materials' response being closer to that of a metallic in the specified energy range. WSeS and WSeTe exhibit peaks in epsilon 2(omega) 2 (omega) representing the highest densities of electronic states that can take part in optical transitions. As fewer states become accessible for the high-energy transitions that make these materials ideal for use in optoelectronics and photovoltaics, as confirmed by the n(omega) decreases as a result of a drop in absorption. The behavior of charge carriers and their interactions with the lattices leads to an almost linear increase in electrical thermal conductivity with temperature. Because electron-phonon scattering, the main type of scattering, increases with temperature, electrical conductivity in these materials often decreases as temperature rises.