Insight into structural stability, electronic, optical and thermoelectric properties of the inverse perovskite Na3SCl compound from first-principles study

Abstract

In the present work, we give a thorough analysis of the cubic inverse-perovskite Na3SCl's structural, electrical, optical, and thermoelectric properties using the FP-LAPW approach within the context of DFT. PBE-GGA has espoused for exchange-correlation the potential for the evaluation of structural characteristics. A well-known accurate potential for the computation of electronic structures known as TB-mBJ has also been added along with PBE-GGA for the computations of band structures and their density of states. The probe of cohesive energy, formation energy, and elastic aspects demonstrates that the material under study is chemically, and thermodynamically stable. The obtained lattice parameters and other structural data of the investigated Na3SCl are in well agreement with the reported results of similar compounds. A direct band gap of 3.493 eV identified from the band structure for Na3SCl demonstrates the semiconducting character of the examined antiperovskite. Charge density contours analysis reveals that Na3SCl possesses an ionic nature, which is confirmed by electron localization function (ELF) analysis. We additionally assessed optical constants for the Na3SCl, such as the dielectric function, optical reflectivity, refractive index, and electron energy loss, with radiation up to 12 eV. Furthermore, variations in temperature-dependent thermoelectric features in terms of Seebeck coefficient, thermal conductivity, electrical conductivity, power factor, and figure of merit have been determined for the first time using the BoltzTraP code. The perovskite under study has a p-type semiconducting nature, as indicated by the estimated positive Seebeck value, and holes rather than electrons are the predominant charge carriers for conduction. The obtained substantial figure of merit along with the low thermal-to-electrical conductivity ratio for the examined inverse perovskite imply it is suitable for thermoelectric applications in devices. Our examined Na3SCl inverse perovskite offers a fruitful framework for enhancing comprehensive TE efficacy for TE usage and green energy generation.