Study of mechanical, thermodynamic, thermoelectric, and optical properties of Cs2SbAuX6 (X = Cl, Br, I) for energy harvesting applications

Abstract

The inorganic double perovskites (DPs) Cs2SbAuX6 (X = Cl, Br, I) are an emerging applicant for solar cells, optoelectronic, and thermoelectrics to acquire clean energy. Therefore, the present research thoroughly addresses the mechanical, thermodynamic, optical, and thermoelectric characteristics by modified Becke and Johnson potential of Trans and Balaha (TB-mBJ) and BoltzTraP code. The structural stability is narrated from the tolerance factor and thermodynamic stability by formation energy. Born criteria assure the mechanical existence of cubic structures. The Cs2SbAu(Cl/Br)6 is ductile, and Cs2SbAuI6 has brittle behavior with a metallic nature. The band structures analysis reports the narrow band gaps for Cl/Br and the zero band gap for I-based DPs. The optical properties are studied by dielectric constants, absorption bands, refractive index, and other dependent optical parameters. Lastly, thermoelectric characteristics regarding Seebeck coefficient, electrical conductivity, power factor, thermal conductivity, and figure of merit in the temperature range 200–600K are analyzed. ZT's significant value at room temperature makes them potential candidates for thermoelectric generators.