Effect of ultra - violet laser treatment on multi - wall carbon nanotube surface

Well-aligned multi-wall carbon nanotubes (MWCNTs) have been grown on both Coming glass and silicon substrates at about 400 $^{\circ}C$ by a modified plasma - enhanced chemical vapor deposition system. We have investigated laser irradiation effect on carbon nanotube surface by using an ultra - violet laser. The laser operated to modify structural defect of was carbon nanotube and to ablate possible contamination of carbon nanotube surface. The morphology and surface transformation of MWCNTs as analyzed by a SEM. In addition, the field emission measurement was also carried out in a vacuum chamber with a $10^{-7}$ Torr base pressure by applying bias voltages up to 1000V.