Optical measurement of thermal transport in suspended carbon nanotubes

Abstract

Thermal transport in carbon nanotubes is explored using different laser powers to heat suspended single-walled carbon nanotubes ∼5μm in length. The temperature change along the length of a nanotube is determined from the temperature-induced shifts in the G band Raman frequency. The spatial temperature profile reveals the ratio of the contact thermal resistance to the intrinsic thermal resistance of the nanotube. Moreover, the obtained temperature profiles allow differentiation between diffusive and ballistic phonon transport. Diffusive transport is observed in all nanotubes measured and the ratio of thermal contact resistance to intrinsic nanotube thermal resistance is found to range from 0.02 to 17.

Study of the temperature distribution in Si nanowires under microscopic laser beam excitation

“…The temperature distribution along the suspended part of a one-dimensional structure under a local laser beam excitation, which the position is scanned along the NW, was deduced by Hsu et al [33], as to present a parabolic form according to the following expression:…”

“…This configuration has been used for measuring the thermal conductivity of NWs [12, [33][34][35][36][37].…”

“…On the other hand, the experimental approaches to measure the thermal conductivity of NWs face the difficulties of measuring the temperature at the nanometer scale, and the poor heat flow between the NW and the measurement resistors in thermal bridges. In this context, the use of optical beams as contactless thermal probes appears as an attractive approach for the measurement of the thermal conductivity of NWs, making use of the temperature dependence of certain optical properties, which can be used as local thermometers [12, [33][34][35][36][37]. One of the critical issues when using laser beams as probe vehicles for NWs characterization is purely geometric, because the diameters of the NWs are substantially smaller than the laser beam diameter used for electro-optical characterization experiments, e.g., Raman, PL, PC.…”

Synthesis and Diameter-dependent Thermal Conductivity of InAs Nanowires

“…On the other hand, one end of the NWs embedded into the carbon conductive adhesive, which results in large area of heat dissipation. So the temperature of contact point is almost equal to the room temperature, and the contact thermal resistances (R c ) between the NWs and the conductive adhesive can be neglected [28]. In this work, we measured the thermal conductivity of InAs NWs with different diameters using this laser heating method.…”

“…Therefore, the _ Q c and _ Q r are negligible, and the formula _ Q ci ¼ P abs can be conducted. A simple model to describe the heat conduction in one-dimensional nanostructures has been reported by Hsu et al [28], which is…”