Photoluminescence changes of C₇₀ nanotubes induced by laser irradiation

C₇₀ nanotubes with a fcc lattice structure are polymerized through being irradiated by lasers with a wavelength of 514.5 nm at various power values. Raman spectra and photoluminescence (PL) spectra are employed to characterize the polymeric phases of the laser treated samples, showing that the disordered C₇₀ oligomers are formed in the C₇₀ nanotubes irradiated by such strong green lasers. Comparative studies further indicate that intermolecular bonds are formed between C₇₀ molecules on the surface of nanotubes, which are similar to those formed under high pressure and high temperature (HPHT) conditions. And the content of intermolecular bonds increases obviously with the laser power increasing.