Manipulating Thermal Conductance of Supported Graphene via Surface Hydroxylation of Substrates
| Autor: | Zhao Li, Gaosheng Wei, Liu Cui, San-Qiang Shi, Xiaoze Du |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Phonon
Graphene 02 engineering and technology Substrate (electronics) 021001 nanoscience & nanotechnology Thermal conduction 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Amorphous solid Hydroxylation chemistry.chemical_compound General Energy Thermal conductivity chemistry Chemical physics law 0103 physical sciences Physics::Atomic and Molecular Clusters Surface modification Physics::Chemical Physics Physical and Theoretical Chemistry 010306 general physics 0210 nano-technology |
| Zdroj: | The Journal of Physical Chemistry C. 122:27689-27695 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | Surface functionalization of substrates is a promising strategy to tune thermal transport in supported graphene. In this work, we have conducted molecular dynamics simulations to investigate how the surface hydroxylation of amorphous SiO2 substrate affects heat conduction in supported graphene. The results show that the thermal conductivity of supported graphene is decreased by introducing hydroxyl groups on the substrate surface. The underlying physics of thermal conductivity suppression is explained by analyzing the phonon spectral energy density, lifetime, and participation ratio. We have observed that the surface hydroxylation decreases the phonon lifetime and causes remarkable damping of out-of-plane flexural phonons. Moreover, the hydroxyl groups induce modifications of the graphene configuration, which result in the phonon localization and, correspondingly, the low thermal conductivity. Our findings highlight the importance of the substrate surface on thermal conductivity of supported graphene and ... |
| Databáze: | OpenAIRE |
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