Thermal analysis of carbon nanotube film irradiated by a pulsed laser

The prepared multi-walled carbon nanotubes (MWCNTs) film was mounted on the holder and the film surface was flashed with a single pulse of Nd:YAG laser (λ = 532 nm) or a pulsed KrF excimer laser (λ = 248 nm) in the air. The threshold energy density for surface damage was measured by inspecting the surface morphology. The dynamics of pulsed nanosecond laser heating process was simulated by the solution of the one-dimensional heat conduction equation. The finite element method (FEM) was applied to solve the equation. The damage threshold energy density for MWCNTs films flashed by a pulsed Nd:YAG laser were in the range 650 mJ/cm2 and 790 mJ/cm2. At the laser fluence of 790 mJ/cm2 with Nd:YAG laser, the surface reached the maximum temperature 913 °C at 13 ns. Moreover, the Raman spectroscopy of MWCNTs films before and after irradiation were measured. Graphitization occurred on the sample after irradiation over the threshold energy of surface damage.