A technique was reported that was able to create low-energy hydrogen ion-induced defects on single-walled carbon nanotube using a hydrogen electron cyclotron resonance plasma source. Low-temperature scanning tunneling microscopy investigations revealed defect sites with hillock-like features between 1 and 3 in height and lateral spreading of between 0.5 and 2nm. Scanning tunneling spectroscopy measurements of metallic single-walled carbon nanotubes revealed marked modification of the electronic structure of a specific defect zone characterized by a pronounced peak in the local density of states close to the Fermi energy.

Creation and STM/STS Investigations of Hydrogen Ions Induced Defects on Single-Walled Carbon Nanotubes. G.Buchs, P.Ruffieux, P.Gröning, O.Gröning: Journal of Physics - Conference Series, 2007, 61[1], 160-5