Thermal and Structural Characterizations of Individual Single‐, Double‐, and Multi‐Walled Carbon Nanotubes

Abstract

Thermal conductance measurements of individual single‐ (S), double‐ (D), and multi‐ (M) walled (W) carbon nanotubes (CNTs) grown using thermal chemical vapor deposition between two suspended microthermometers are reported. The crystal structure of the measured CNT samples is characterized in detail using transmission electron microscopy (TEM). The thermal conductance, diameter, and chirality are all determined on the same individual SWCNT. The thermal contact resistance per unit length is obtained as 78–585 m K W−1 for three as‐grown 10–14 nm diameter MWCNTs on rough Pt electrodes, and decreases by more than 2 times after the deposition of amorphous platinum–carbon composites at the contacts. The obtained intrinsic thermal conductivity of approximately 42–48, 178–336, and 269–343 W m−1 K−1 at room‐temperature for the three MWCNT samples correlates well with TEM‐observed defects spaced approximately 13, 20, and 29 nm apart, respectively; whereas the effective thermal conductivity is found to be limited by the thermal contact resistance to be about 600 W m−1 K−1 at room temperature for the as‐grown DWCNT and SWCNT samples without the contact deposition.

Controlling the thermal contact resistance of a carbon nanotube heat spreader

“…2,[5][6][7][8][9][10][11][12] This incongruity in some cases can be attributed to variations in thermal contact resistance R c , 13 a parameter that has recently received much attention, with studies on the subject reporting values that vary widely. 13,[14][15][16][17][18][19][20][21][22] For example, Maune et al perform thermometry employing electrical breakdown of CNTs to report R c values of 0.6--3.0 K·m/W, 15 whereas Tsen et al…”

Reexamination of basal plane thermal conductivity of suspended graphene samples measured by electro-thermal micro-bridge methods

“…Although these values are much smaller than the actual suspended lengths and widths of these samples, a low interface transmission coefficient between the supported and suspended graphene segments can reduce the effective boundary length to α λ L, as illustrated in Equation (4). In addition, the calculation result becomes higher than the measurement data at temperatures above 250 K for the bi-layer graphene sample of Pettes et al 30 However, the discrepancy can still be attributed to either a frequency-dependent α, which is lower for the higher frequency phonons, 12 or additional point defect scattering, which is also more pronounced for the higher frequency phonons populated at higher temperatures. In particular, among the three samples examined here, only this bi-layer sample was exposed to electron beam irradiation during the sample preparation process.…”

“…The interface heat transfer between the supported graphene segment and the support results in a hyperbolic temperature distribution in the supported graphene segment, similar to that found along a fin with the base connected to a heat source and the circumference surface exposed to a reservoir at a different temperature. 28 Hence, a fin resistance model has been developed in prior works for the calculation of the sample-support interface thermal resistance as [29][30][31][32] …”

n-Type Carbon Nanotubes/Silver Telluride Nanohybrid Buckypaper with a High-Thermoelectric Figure of Merit

“…Owning to these advanced properties as well as abundance of carbon on the earth, CNT is an important candidate to build flexible electronics. [25][26][27] However, it is seldom regarded as a TE material due to its poor Seebeck coefficient (< 60 μV/K) 28 and high thermal conductivity of a single tube (~ 250-10000 Wm -1 K -1 for single tube or aligned arrays) [29][30][31] . It has been reported that low thermal conductivities can be obtained in CNTs/conductive polymer composites and processed tubes.…”