Experimental study of the thermal conductivity of single-walled carbon nanotube-based thin films

The single-walled carbon nanotube-based thin films with a thickness from 11 $\pm$ 3 to 157 $\pm$ 18 nm have been formed using vacuum filtration. The thermal conductivity of the thin films as a function of thickness and temperature up to 450 K has been studied by the 3$\omega$ technique. It has been found that, in the region of 49 nm, the supplied heat from a gold strip started propagating with the high efficiency to the thin film plane. The thermal conductivity of the thin films with a thickness of 49 $\pm$ 8 nm was measured using the 3$\omega$ technique for bulk samples. It has been found that the thermal conductivity of the single-walled carbon nanotube-based thin films strongly depends on their thickness and temperature. The thermal conductivity sharply (by a factor of $\sim$ 60) increases with an increase in thickness from 11 $\pm$ 3 to 65 $\pm$ 4 nm. In addition, it has been observed that the thermal conductivity of the thin film with a thickness of 157 $\pm$ 18 nm rapidly decreases from 211 $\pm$ 11 to 27.5 $\pm$ 1.4 W m$^{-1}$ K$^{-1}$ at 300 and 450 K, respectively.