Thermal Transport in Graphene Nanomesh: Unraveling the Role of Brillouin Zone Folding, Phonon Localization and Phonon Confinement
Autor: | Liu Cui, Xiaoze Du, Zhao Li, Gaosheng Wei |
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Rok vydání: | 2021 |
Předmět: |
Materials science
Phonon 02 engineering and technology 01 natural sciences 010305 fluids & plasmas law.invention Condensed Matter::Materials Science chemistry.chemical_compound Thermal conductivity Thermal insulation law Condensed Matter::Superconductivity 0103 physical sciences Fluid Flow and Transfer Processes Condensed matter physics business.industry Graphene Mechanical Engineering Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Condensed Matter Physics Thermal conduction Thermoelectric materials Brillouin zone Nanomesh chemistry Condensed Matter::Strongly Correlated Electrons 0210 nano-technology business |
Zdroj: | International Journal of Heat and Mass Transfer. 165:120685 |
ISSN: | 0017-9310 |
Popis: | Coherent thermal transport has recently become a subject of considerable interest, but whether some intriguing phenomena of phonon coherence (including Brillouin zone folding, phonon localization, and phonon confinement) occur in certain nanostructures remains unclear. We have investigated the thermal transport in graphene nanomesh using molecular dynamics simulations together with first-principles calculations. It is found that the thermal conductivity of nanomesh is significantly reduced compared with graphene, mainly due to the bandgaps, flattened phonon dispersions and reduced phonon group velocities induced by Brillouin zone folding. Meanwhile, the significant decrease in thermal conductivity is induced by phonon localization. Phonon confinement caused by reflecting the optical phonon modes back into the C-H part further leads to the reduction of thermal conductivity. We highlight the coherent mechanism for lowering thermal conductivity, which is useful for manipulating heat conduction for thermoelectrics and thermal insulation applications. |
Databáze: | OpenAIRE |
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