Structural, electronic, optical, and thermoelectric response of zintl phase AAg2S2 (A= Sr/Ba) compounds for renewable energy applications

Abstract

In this study, we investigated the structural, electronic, optical, and thermal characteristics of AAg2S2 (A = Sr/Ba) compounds using the first-principles method. We discovered that the trigonal structure of these compounds is dynamically stable and that their phonon spectra do not contain any negative frequencies. The computed bandgaps are 2.05 eV and 1.97 eV for AAg2S2 (A = Sr/Ba) compounds respectively. The optical properties of the investigated compounds are determined energy range 0–10 eV in terms of dielectric constant, refractive index, energy loss function etc. The presence of absorption peaks in visible region confirms the transfer of electron from the valence band to conduction band. BoltzTrap program on Wein2K code has been used to study the material thermoelectric properties. Due to its excellent optoelectronic characteristics and extraordinary power factor values, this family may show potential for application in optoelectronic and thermal devices.