Substrate Effects on the Thermal Conductivity of Single Layer Supported Graphene

2011 ◽  
Author(s):  
Z. Wei ◽  
C. Dames ◽  
Y. Chen
Keyword(s):  
Thermal Conductivity ◽  
Silicon Dioxide ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Dynamics Model ◽  
Graphene Flake ◽  
Substrate Effects ◽  
Layer Graphene ◽  
Lennard Jones ◽  
Non Equilibrium Molecular Dynamics

A non-equilibrium molecular dynamics model is developed to calculate the thermal conductivity of single layer graphene supported on silicon dioxide. We use the Tersoff potential to describe the carbon-carbon interactions within graphene, and a Lennard-Jones (LJ) potential to describe the interactions between graphene and silicon dioxide. To overcome possible artifacts of thermal expansion, the model avoids using any periodic or fixed boundary conditions for the graphene flake. For both smooth and rough substrates, the simulations show that increasing the LJ coupling strength between graphene and substrate can reduce the in-plane thermal conductivity of graphene. We also investigated the effects of roughness. The simulations show that the thermal conductivity is sensitive to the roughness only when the coupling is large. These results indicate how the thermal properties of graphene may be modified by adjusting the coupling and roughness of the substrate.

Thermal Conductivity Reduction in Few-Layer Graphene

2011 ◽  
Author(s):  
Dhruv Singh ◽  
Jayathi Y. Murthy ◽  
Timothy S. Fisher
Keyword(s):  
Thermal Conductivity ◽  
Weak Coupling ◽  
Phonon Scattering ◽  
Single Layer ◽  
Acoustic Mode ◽  
Single Layer Graphene ◽  
Boltzmann Transport ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Few Layer Graphene

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. The highly restrictive selection rule that leads to a high thermal conductivity of ZA phonons in single-layer graphene is only weakly broken with the addition of multiple layers, and ZA phonons still dominate thermal conductivity. We also find that the decrease in thermal conductivity is mainly caused by decreased contributions of the higher-order overtones of the fundamental out-of-plane acoustic mode. Moreover, the extent of reduction is largest when going from single to bilayer graphene and saturates for four layers. The results compare remarkably well over the entire temperature range with measurements of of graphene and graphite.

Mode dependent lattice thermal conductivity of single layer graphene

2014 ◽  
Vol 116 (15) ◽  
pp. 153503 ◽  
Author(s):  
Zhiyong Wei ◽  
Juekuan Yang ◽  
Kedong Bi ◽  
Yunfei Chen
Keyword(s):  
Thermal Conductivity ◽  
Lattice Thermal Conductivity ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Layer Graphene

Tuning Thermal Conductivity With Mechanical Strain

2010 ◽  
Author(s):  
Xiaobo Li ◽  
Jun Liu ◽  
Ronggui Yang
Keyword(s):  
Thermal Conductivity ◽  
Silicon Nanowires ◽  
Phonon Dispersion ◽  
Compressive Strain ◽  
Mechanical Strain ◽  
Single Layer ◽  
Polymer Materials ◽  
Single Layer Graphene ◽  
Layer Graphene ◽  
Carbon Based

Mechanical strain provides an efficient way for tuning thermal conductivity of materials. In this study, molecular dynamics (MD) simulation is performed to systematically study the strain effects on the lattice thermal conductivity of silicon and carbon based materials (mainly nanostructures: Si nanowire and thin film, single-walled carbon naotube (SWCNT) and single layer graphene) and bulk polymer materials. Results show that thermal conductivity of the strained silicon nanowires and thin films decreases continuously when the strain changes from compressive to tensile. However, the thermal conductivity has a peak value under compressive strain for SWCNT and at zero strain for single layer graphene. In contrast, thermal conductivity of polymer materials increases with increasing tensile strain. The underlying mechanisms are analyzed in this paper for both types of materials. We found that the thermal conductivity of silicon and carbon based materials can be related to the phonon dispersion curve shift and structural buckling under strain and for polymer chains thermal conductivity directly connects to the orientations of the chains. This thermal conductivity dependence with strain can guide us to tune the thermal conductivity for materials in applications.

scholarly journals Молекулы фуллерена C-=SUB=-60-=/SUB=- под однослойным графеном на металлической подложке

2021 ◽  
Vol 55 (7) ◽  
pp. 592
Author(s):  
С.Ш. Рехвиашвили ◽  
М.М. Бухурова
Keyword(s):  
Specific Interaction ◽  
Single Layer ◽  
Single Layer Graphene ◽  
C60 Fullerene ◽  
Jones Potential ◽  
Hybrid Nanomaterial ◽  
Layer Graphene ◽  
Lennard Jones ◽  
Thick Substrate ◽  
Theoretical Results

The article discusses a hybrid nanomaterial - a monolayer of C60 molecules, which is located between a single-layer graphene and a metal substrate. Using the Lennard-Jones potential, formulas for the specific interaction energy of C60 fullerene molecules with single-layer graphene and a thick substrate are obtained. The specific energy of graphene adhesion and the equilibrium parameters of the considered nanostructure are calculated. The obtained theoretical results agree with the available experimental results.

First Principles Study of Interlayer Interaction Effect on Graphene Thermal Conductivity

2019 ◽  
Author(s):  
Yuan Dong ◽  
Chi Zhang ◽  
Chenghao Diao ◽  
Jian Lin
Keyword(s):  
Thermal Conductivity ◽  
Phonon Dispersion ◽  
Single Layer ◽  
Theoretical Aspect ◽  
Single Layer Graphene ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Multiple Layer ◽  
Phonon Properties ◽  
Vdw Interaction

Abstract It is known that the interlayer van der Waals (vdW) interactions will decrease the thermal conductivity of graphene. Single layer graphene (SLG) has the highest thermal conductivities, double layer graphene (DLG) would decrease to about half of the thermal conductivity of SLG. The graphite was measured to have a thermal conductivity of about 2000 W/m-K. Some research shows that graphite differs from SLG within a factor of 2, and DLG has almost the same thermal conductivity with graphite. In theoretical aspect, how to simulate the vdW interaction between graphene layers is a long existing problem. It is only until recently that the vdW interaction is still an active topic in first principle calculations. The popular methods include the Grimme’s DFT-D, vdW-DF and vdW-DFT-R methods. The vdW-DFT-R method was further optimized to increase accuracy by Hamada and was found to predict the most accurate interlayer distance between AB-stacked graphene in our recent study. The motivation of this work is to investigate the effect of vdW interaction on the thermal conductivity of multiple layer graphene from principles. We will calculate firstly the phonon dispersion relations of multiple layer graphene with the vdW interaction included. The obtained phonon properties and force constants will be combined with the ShengBTE method to calculate the thermal conductivity. The results show how vdW interaction causes the dimensional crossover of graphene thermal conductivity.

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