Vibrational and transport phenomenon in Cs2CdZnCl6 double perovskite: A DFT study

Abstract

This study aims to study of physical parameters of the Cs2CdZnCl6 double perovskite compound implementing a full-potential linearized augmented plane wave (FP-LAPW) technique and Boltzmann transport equation within the framework of density functional theory (DFT) as carried out in the WIEN2k code. The Birch Murnaghan equation of state (EOS) and the generalized gradient approximation (GGA) were both used in the structural analysis, resulting in the stable phase for Cs2CdZnCl6 double perovskite. The compound is found to be semiconductor in nature with band gap of 3.971 eV. Strong hybridization between the Cd-3d and Zn-5d orbitals was seen in the DOS data, confirming the ionic character due to the relative abundances of the two states. Thermodynamic features have been computed for temperature ranges (0−1200K) and pressure ranges of around 0–30 GPa, In regard to thermoelectric properties, calculations have been made for temperature, chemical potential, and charge carrier concentrations. Positive values of the Seebeck coefficient characterize the p-type nature of Cs2CdZnCl6. The highest Seebeck coefficient ever recorded was 235.41 mV/K at 130 K. According to calculations, the maximum ZT value at 600 K is 0.65, which raises the possibility that Cs2CdZnCl6 is a high-performance thermoelectric material.