Ab initio study of the optoelectronic and thermoelectric properties of the new double perovskite Cs2ZnPbX6(X=Br, Cl)

This study investigates the structural, optoelectronic, thermodynamic, and thermoelectric properties of the new double perovskite compounds Cs2ZnPbCl6 and Cs2ZnPbBr6 utilizing advanced computational methods. We analyze the stability and electronic characteristics of these materials in their cubic phase (space group Fm-3 m). Our findings reveal that both compounds exhibit promising thermoelectric performance, with peak Seebeck coefficients of 2880 mu V/K for Cs2ZnPbBr6 and 2870 mu V/K for Cs2ZnPbCl6 at 300 K. The electrical conductivity (sigma/tau) values reach 11.66 and 10.98, respectively, indicating strong carrier mobility. Additionally, we observe significant changes in the Seebeck coefficient as a function of carrier concentration, attributed to the formation of electron-hole pairs and shifts in the Fermi level. Finally, the thermodynamic and thermoelectric attributes suggest that the double perovskite materials investigated hold promise for implementation in thermoelectric technology, showcasing a favorable figure of merit at ambient temperature.