Strain Effect on Rashba Splitting and Phonon Scattering to Improve Thermoelectric Performance of 2D Heterobilayer MoTe2/PtS2
Journal
ACS Applied Energy Materials
Journal Volume
8
Journal Issue
13
Start Page
9617
End Page
9626
ISSN
25740962
Date Issued
2025
Author(s)
van Thanh, Vuong
Abstract
Rashba spin-orbit coupling significantly modifies the electronic band structure in two-dimensional (2D) van der Waals (vdW) heterobilayers, which may enhance their thermoelectric (TE) properties. In this study, we use first-principles calculations and Boltzmann transport theory to explore the effect of strain on the TE performance of 2D vdW heterobilayer MoTe2/PtS2. A strong Rashba spin-splitting is observed in the valence band, resulting in an increase in the Seebeck coefficient for the p-type. The lattice thermal conductivity of MoTe2/PtS2 is remarkably low, about 0.6 W m-1 K-1 at 300 K, due to large anharmonic scattering. Furthermore, biaxial strain enhances the power factor (PF) by introducing band convergence. At a strain of 2%, the optimal PF for the n-type material reaches 170 μW/cmK2, indicating an approximately 84.78% increase compared to the unstrained state (92 μW/cmK2). Given the low lattice thermal conductivity, the optimized figure of merit ZT achieves up to 0.88 at 900 K for the n-type. Our findings indicate that MoTe2/PtS2 is a highly promising candidate for 2D heterobilayer TE materials owing to its strong Rashba splitting and significant anharmonicity.
Subjects
2d Van Der Waals Heterobilayer Mote2/pts2
Anharmonicity
Band Convergence
Density Functional Theory
Rashba Spin?orbit Coupling
Thermoelectricity
Crystal Lattices
Molybdenum Compounds
Statistical Mechanics
Tellurium Compounds
Thermal Conductivity
Thermoelectricity
Anharmonicities
Band Convergence
Density-functional-theory
Lattice Thermal Conductivity
Rashba Spin-orbit Coupling
Splittings
Thermoelectric Performance
Two-dimensional
Two-dimensional Van Der Waal Heterobilayer Mote2/pts2
Van Der Waal
Density Functional Theory
Publisher
American Chemical Society
Type
journal article