Thermoelectric properties of asymmetric low-dimensional Pt2ClF from ab initio calculation

Abstract

Finding thermoelectric materials with high figures of merit is a significant and ongoing research topic. A testbed of intriguing structures is made up of the candidate materials with low dimensional structures. In this study, we investigate the thermoelectric properties of low-dimensional Pt₂Cl₂ and Pt₂ClF structures using first-principles calculations based on Density Functional Theory (DFT). Anharmonic effects, phonon transport properties, and lattice thermal conductivity were thoroughly analyzed. The results indicate that the asymmetric Pt₂ClF structure exhibits significantly stronger anharmonicity compared to its symmetric counterpart, Pt₂Cl₂. This enhanced anharmonicity arises from the asymmetry introduced by fluorine substitution, which increases phonon–phonon scattering and reduces the lattice’s thermal conductivity. This makes the figure of merit higher for Pt₂ClF. These findings suggest that the asymmetric Pt₂ClF structure, with its enhanced phonon scattering mechanisms and suppressed lattice thermal conductivity, is a promising material for high-temperature thermoelectric applications.