Electron Drag Effect on Thermal Conductivity in Two-dimensional Semiconductors

Fuente: arXiv
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Main Authors: Quan, Yujie, Liao, Bolin
Format: Preprint
Published: 2024
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author Quan, Yujie
Liao, Bolin
author_facet Quan, Yujie
Liao, Bolin
contents Two-dimensional (2D) materials have shown great potential in applications as transistors, where thermal dissipation becomes crucial because of the increasing energy density. Although thermal conductivity of 2D materials has been extensively studied, interactions between nonequilibrium electrons and phonons, which can be strong when high electric fields and heat current coexist, are not considered. In this work, we systematically study the electron drag effect, where nonequilibrium electrons impart momenta to phonons and influence the thermal conductivity, in 2D semiconductors using ab initio simulations. We find that, at room temperature, electron drag can significantly increase thermal conductivity by decreasing phonon-electron scattering in 2D semiconductors, while its impact in three-dimensional (3D) semiconductors is negligible. We attribute this difference to the large electron-phonon scattering phase space and higher contribution to thermal conductivity by drag-active phonons. Our work elucidates the fundamental physics underlying coupled electron-phonon transport in materials of various dimensionalities.
format Preprint
id arxiv_https___arxiv_org_abs_2405_02257
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Electron Drag Effect on Thermal Conductivity in Two-dimensional Semiconductors
Quan, Yujie
Liao, Bolin
Materials Science
Two-dimensional (2D) materials have shown great potential in applications as transistors, where thermal dissipation becomes crucial because of the increasing energy density. Although thermal conductivity of 2D materials has been extensively studied, interactions between nonequilibrium electrons and phonons, which can be strong when high electric fields and heat current coexist, are not considered. In this work, we systematically study the electron drag effect, where nonequilibrium electrons impart momenta to phonons and influence the thermal conductivity, in 2D semiconductors using ab initio simulations. We find that, at room temperature, electron drag can significantly increase thermal conductivity by decreasing phonon-electron scattering in 2D semiconductors, while its impact in three-dimensional (3D) semiconductors is negligible. We attribute this difference to the large electron-phonon scattering phase space and higher contribution to thermal conductivity by drag-active phonons. Our work elucidates the fundamental physics underlying coupled electron-phonon transport in materials of various dimensionalities.
title Electron Drag Effect on Thermal Conductivity in Two-dimensional Semiconductors
topic Materials Science
url https://arxiv.org/abs/2405.02257