High-pressure optical absorption studies of double-walled carbon nanotubes.

International audienceIn this Letter the electronic properties of double-walled carbon nanotubes (DWCNTs) were studied by transmission measurements as a function of hydrostatic pressure up to 10 GPa. The energies of the optical transitions between the Van Hove singularities decrease with increasing pressure, which can be attributed to pressure-induced hybridization and symmetry-breaking effects. We observed a linear behaviour in the pressure-induced shift of the optical transitions. This is in good agreement with previous studies on single-walled carbon nanotubes (SWCNTs). High-resolution TEM image of a bundle of DWCNTs (A), histogram of the number of walls (B), and diameter distribution for CNT samples plotted from 100 HRTEM images (C)