Highly In-Plane Anisotropic 2D-ZrGeTe4: A Promising Thermoelectric Material with a High Power Factor and Figure of Merit
Journal
ACS Applied Energy Materials
Journal Volume
8
Journal Issue
9
Start Page
5721
End Page
5728
ISSN
25740962
Date Issued
2025
Author(s)
Abstract
Two-dimensional (2D) ternary transition metal chalcogenides (TMCs) are promising for thermoelectric (TE) applications because of their low structural symmetry, high in-plane anisotropy, and adjustable band gap. A high-performance TE material requires high electrical conductivity, a large power factor PF, and a sizable dimensionless figure of merit ZT. This study focuses on the TE properties, including electrical and phonon transport properties, of highly in-plane anisotropic 2D-ZrGeTe4 based on combined first-principles and semiclassical Boltzmann theory. First, our results prove that 2D-ZrGeTe4 is mechanically, dynamically, and thermodynamically stable as a free-standing monolayer, which can be attributed to the van der Waals nature of ZrGeTe4. Next, we show that ZrGeTe4 exhibits a tunable band gap, exhibiting an indirect-to-direct band gap transition from the 3D bulk to the 2D monolayer. The electron and hole mobilities are highly anisotropic and dominate in the x-direction. Furthermore, 2D-ZrGeTe4 exhibits a large PF and low lattice thermal conductivity, yielding a high theoretical ZT of 6 and 3 for n-type and p-type at 900 K, respectively. Owing to its rich anisotropy, band degeneracy capabilities, and extreme phonon anharmonicity, 2D-ZrGeTe4 could emerge as a promising candidate for advanced TE applications at high-temperature ranges.
Subjects
2d-zrgete4
Boltzmann Transport Equations
Density Function Theory
In-plane Anisotropy
Thermoelectricity
Valley Degeneracy
Boltzmann Equation
Germanium Compounds
High Temperature Applications
Monolayers
Palladium Compounds
Selenium Compounds
Tellurium Compounds
Tungsten Compounds
Van Der Waals Forces
Boltzmann's Transport Equations
Density Function Theory
Highpower-factor
In-plane Anisotropy
Thermo-electric Materials
Thermoelectric Application
Thermoelectric Material
Two-dimensional
Two-dimensional-zrgete4
Valley Degeneracy
Anisotropy
Publisher
American Chemical Society
Type
journal article