Carbon nanotubes on line-patterned substrates: Raman spectroscopy

Single-walled carbon nanotubes, confined to lines of a few micron widths on line patterned substrates prepared via micro-contact printing, are studied using Raman spectroscopy. For the CNT tangential mode, the so-called G-band, the Raman intensity shows distinct anisotropy that changes with the polarization directions of the incident and the scattered photons. The anisotropy is more distinct for samples with line-patterns of narrower line-width, which indicates an increasing degree of CNT alignment along the patterned line direction with decreasing patterned line-width.