Strain Effect on Rashba Splitting and Phonon Scattering to Improve Thermoelectric Performance of 2D Heterobilayer MoTe$_{2}$/PtS$_{2}$

Fuente: arXiv
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Main Authors: Van Thanh, Vuong, Hung, Nguyen Tuan
Format: Preprint
Published: 2025
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author Van Thanh, Vuong
Hung, Nguyen Tuan
author_facet Van Thanh, Vuong
Hung, Nguyen Tuan
contents 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 strain effect on the TE performance of the 2D vdW heterobilayer MoTe$_{2}$/PtS$_{2}$. A strong Rashba spin-splitting is observed in the valence band, resulting in an increase in the Seebeck coefficient for p-type. The lattice thermal conductivity of MoTe$_{2}$/PtS$_{2}$ is remarkably low about of 0.6 Wm$^{-1}$K$^{-1}$ at $T = 300$ 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 $μ$W/cmK$^{2}$, indicating approximately 84.78\% increase compared to the unstrained state (92 $μ$W/cmK$^{2}$). Given the low lattice thermal conductivity, the optimized figure of merit $ZT$ achieves up to 0.88 at 900 K for n-type. Our findings indicate that MoTe$_{2}$/PtS$_{2}$ is a highly promising candidate for 2D heterobilayer TE materials, owing to its strong Rashba splitting and significant anharmonicity.
format Preprint
id arxiv_https___arxiv_org_abs_2504_16781
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Strain Effect on Rashba Splitting and Phonon Scattering to Improve Thermoelectric Performance of 2D Heterobilayer MoTe$_{2}$/PtS$_{2}$
Van Thanh, Vuong
Hung, Nguyen Tuan
Materials Science
Applied Physics
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 strain effect on the TE performance of the 2D vdW heterobilayer MoTe$_{2}$/PtS$_{2}$. A strong Rashba spin-splitting is observed in the valence band, resulting in an increase in the Seebeck coefficient for p-type. The lattice thermal conductivity of MoTe$_{2}$/PtS$_{2}$ is remarkably low about of 0.6 Wm$^{-1}$K$^{-1}$ at $T = 300$ 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 $μ$W/cmK$^{2}$, indicating approximately 84.78\% increase compared to the unstrained state (92 $μ$W/cmK$^{2}$). Given the low lattice thermal conductivity, the optimized figure of merit $ZT$ achieves up to 0.88 at 900 K for n-type. Our findings indicate that MoTe$_{2}$/PtS$_{2}$ is a highly promising candidate for 2D heterobilayer TE materials, owing to its strong Rashba splitting and significant anharmonicity.
title Strain Effect on Rashba Splitting and Phonon Scattering to Improve Thermoelectric Performance of 2D Heterobilayer MoTe$_{2}$/PtS$_{2}$
topic Materials Science
Applied Physics
url https://arxiv.org/abs/2504.16781