Ta2Pd3Te8: A potential candidate of 1D van der Waals stacked thermoelectric materials

TL;DR

This study predicts that 1D van der Waals stacked Ta2Pd3Te8 is a promising thermoelectric material with high ZT values, mechanical stability, and strong anisotropic properties, encouraging further research and experimental development.

Contribution

It introduces the first theoretical prediction of 1D vdW stacked Ta2Pd3Te8 as a thermoelectric candidate using comprehensive computational methods.

Findings

Ta2Pd3Te8 has high mechanical, dynamical, and thermal stability.

The material exhibits high power factor and low lattice thermal conductivity.

ZT values reach up to 0.48 for n-type at 900 K, with potential to increase to 1.11 by bandgap tuning.

Abstract

Discovering new thermoelectric (TE) materials is an eternal goal in the TE field. Excellent TE materials have ranged from 3D stacked to 2D stacked bulk. However, the 1D stacked receives little attention due to the scarcity in quantity. In this work, it is predicted that 1D van der Waals (vdW) stacked Ta2Pd3Te8 crystal is a compelling candidate for TE applications by combining first-principles calculations with phonon and electron Boltzmann transport equations and molecular dynamics methods. We find that Ta2Pd3Te8 crystal has mechanical, dynamical, and thermal stabilities, and its TE properties are featured by strong anisotropy, high power factor (PF) and low lattice thermal conductivity. The results indicate the ZT values of n-type Ta2Pd3Te8 at 900 K along a, b and c axes reach 0.48, 0.39 and 0.22, respectively. We propose that enlarging the bandgap can weaken the bipolar effect and thus significantly increases ZT to 1.11. The findings in the work not only stimulate more theoretical works on 1D vdW stacked TE materials, but also provide valuable information for experimentally improving TE materials.