Intrinsic anisotropy of thermal conductance in graphene nanoribbons

Xu, Yong; Chen, Xiaobin; Gu, Bing-Lin; Duan, Wenhui

doi:10.1063/1.3272678

Cited by 189 publications

(175 citation statements)

References 22 publications

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“…Due to different boundary condition, intrinsic anisotropy thermal conductivity of GNR is reported. 114 As shown in Fig. 7(a), the room temperature thermal conductance of zigzag GNR is about thirty percent larger than that of armchiar GNR.…”

Section: B 2d Nanostructuresmentioning

confidence: 94%

“…There are rich physical phenomena about thermal property of GNRs. The effects of size, [95][96][97][98] defects, 99, 100 doping, 101,102 shape, 103,104 stress/strain,, [105][106][107][108] substrates, 109 inter-layer interactions, [110][111][112] nanoscale junctions, 113 chirality, 114 topological structure, 115 edge effect, [116][117][118][119] foldings (gradfolds), 23,120 etc. on thermal conductivity of nanoribbons [121][122][123][124][125][126][127][128] have been widely studied.…”

Section: B 2d Nanostructuresmentioning

confidence: 99%

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Thermal transport in nanostructures

et al. 2012

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This review summarizes recent studies of thermal transport in nanoscaled semiconductors. Different from bulk materials, new physics and novel thermal properties arise in low dimensional nanostructures, such as the abnormal heat conduction, the size dependence of thermal conductivity, phonon boundary/edge scatterings. It is also demonstrated that phonons transport super-diffusively in low dimensional structures, in other words, Fourier's law is not applicable. Based on manipulating phonons, we also discuss envisioned applications of nanostructures in a broad area, ranging from thermoelectrics, heat dissipation to phononic devices.

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Section: B 2d Nanostructuresmentioning

confidence: 94%

Section: B 2d Nanostructuresmentioning

confidence: 99%

Thermal transport in nanostructures

et al. 2012

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“…The measured value of thermal conductivity of graphene reaches as high as several thousand of watt per meter Kelvin, [7][8][9][10] among the highest values of known materials. Previous studies [11][12][13] show that the thermal transport in GNRs depends on the edge chirality of GNRs. In realistic graphene samples, the edges are often passivated [14][15][16] and the isotope composition can be controlled.…”

mentioning

confidence: 99%

“…Within each slice ͓such as the dashed box in the inset of Fig. 3͑b͔͒, the number ͑L͒ of vertical 13 C atomic chains with zigzag shape ͓e.g., L = 4 for the inset of Fig. 3͑b͔͒ can vary from 0 to 7 ͑see details in Ref.…”

mentioning

confidence: 99%

Tuning the thermal conductivity of graphene nanoribbons by edge passivation and isotope engineering: A molecular dynamics study

Hu¹,

Schiffli²,

Vallabhaneni³

et al. 2010

Applied Physics Letters

161

113

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Using classical molecular dynamics simulation, we have studied the effect of edge-passivation by hydrogen (Hpassivation) and isotope mixture (with random or supperlattice distributions) on the thermal conductivity of rectangular graphene nanoribbons (GNRs) (of several nanometers in size). We find that the thermal conductivity is considerably reduced by the edge H-passivation. We also find that the isotope mixing can reduce the thermal conductivities, with the supperlattice distribution giving rise to more reduction than the random distribution. These results can be useful in nanoscale engineering of thermal transport and heat management using GNRs.Graphene 1,2 is a monolayer of graphite with a honeycomb lattice structure. It exhibits many unique properties and has drawn intense attention in the past few years. The unusual electronic properties of graphene are promising in many fundamental studies and applications, e.g., the ultrahigh electron mobility 2 and the tunable band gap and magnetic properties by the size and edge chirality of GNRs. [3][4][5][6] Graphene also has remarkable thermal properties. The measured value of thermal conductivity of graphene reaches as high as several thousand of W/m-K, 7-10 among the highest values of known materials. Previous studies [11][12][13] show that the thermal transport in GNRs depends on the edge chirality of GNRs. In realistic graphene samples, the edges are often passivated [14][15][16] and the isotope composition can be controlled. 17 Motivated by these, we study the effect of the edge H-passivation and various isotope distributions on the thermal transport in GNRs. We find that the thermal conductivity can be reduced by the edge H-passivation and tuned by the isotope distributions. Our study is useful in nanoscale control and management of thermal transport by engineering the chemical composition of GNRs.In this work, we employ the classical molecular dynamics (MD, similar to the method in Ref. 11) to calculate the thermal conductivities of GNRs. We use the Brenner potential, 18 which incorporates the many-body carbon-carbon and carbon-hydrogen interactions by introducing a fractional number of covalent bonds. This method has been successfully applied to many carbonbased systems, 19,20 especially to graphene. 11,21,22 The structures of GNRs are shown in Fig. 1 (with edge H-

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“…Several studies have shown that armchair edge GNRs (AGNRs -the ones considerd in the main text) and zig-zag-GNRs (ZGNRs) differ in thermal conductivity [41,[59][60][61][62]. Thus, we find it instructive to present the corresponding simulation results as in Fig.…”

Section: Appendix: Simulation Data For the Zigzag-edge Gnrs (Zgnrs)mentioning

confidence: 99%

Phonon transport effects in one-dimensional width-modulated graphene nanoribbons

Karamitaheri

Neophytou

2016

Journal of Applied Physics

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We investigate the thermal conductance of one-dimensional periodic widthmodulated graphene nanoribbons using lattice dynamics for the phonon spectrum and the Landauer formalism for phonon transport. We conduct a full investigation considering all relevant geometrical features, i.e. the various lengths and widths of the narrow and wide regions that form the channel. In all cases that we examine, we find that widthmodulation suppresses the thermal conductance at values even up to ~70 % below those of the corresponding uniform narrow nanoribbon. We show that this can be explained by the fact that the phonon spectrum of the width-modulated channels acquires less dispersive bands with lower group velocities and several narrow bandgaps, which reduce the phonon transmission function significantly. The largest degradation in thermal conductance is determined by the geometry of the narrow regions. The geometry of the wider regions also influences thermal conductance, although modestly. Our results add to the ongoing efforts in understanding the details of phonon transport at the nanoscale, and our conclusions are generic and could also apply to other one-dimensional channel materials.

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Intrinsic anisotropy of thermal conductance in graphene nanoribbons

Cited by 189 publications

References 22 publications

Thermal transport in nanostructures

Thermal transport in nanostructures

Tuning the thermal conductivity of graphene nanoribbons by edge passivation and isotope engineering: A molecular dynamics study

Phonon transport effects in one-dimensional width-modulated graphene nanoribbons

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