Optical measurement of thermal transport in suspended carbon nanotubes

Thermal transport in carbon nanotubes is explored using different laser powers to heat suspended single-walled carbon nanotubes similar to 5 mu m 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. (c) 2008 American Institute of Physics.