The Influence of Laser Radiation Power on Raman Spectra of Multi-Walled Carbon Nanotubes

Raman spectrometry is one of the most widely used techniques for the analysis of oriented multi-walled carbon nanotubes (MWCNTs), while the analyzing laser beam is also a source of local heating. The behavior of characteristic peaks in the spectrum of MWCNTs (D, G, 2D(G ), and D ) is monitored by increasing the laser radiation power and then decreasing it to the initial values. An additional peak was introduced to compensate for the difference between the experimental spectrum and the sum of the decomposition components (in the region of 1500 cm ), the character of which differs from the behavior of the known peaks, which indicates the different nature of their origin. It is noted that an increase in laser power leads to a decrease in the number of defects in carbon nanotubes.