Stability and thermoelectric performance of binary chalcogenides: A first-principles perspective

In this study, we conduct a comprehensive first-principles analysis of the thermodynamic stability, electronic transport properties, and mechanical behavior of selected binary chalcogenides to evaluate their potential for thermoelectric applications. Employing the PBE-GGA functional within the VASP framework, the phonon spectra, ab initio molecular dynamics (AIMD), and key electronic and mechanical parameters are investigated. The electronic band structures are estimated with PBE-GGA and mBj potentials. The materials exhibit metallic characteristics, as indicated by partially filled electronic states at the Fermi level. Charge reconstruction and bonding interactions are seen from an electron density difference analysis in CeSe and LaTe, which are specified by their unique electronic configuration. Phonon dispersion and AIMD simulations confirm dynamical and thermal stability, demonstrating their structural resilience under operational conditions. Although the computed thermoelectric figure of merit (ZT) remains moderate under idealized conditions, the findings suggest significant potential for enhancement via electronic structure optimization. These results highlight the investigated binary chalcogenides as promising candidates for stable and efficient thermoelectric devices.