Substitutional Si doping in deformed carbon nanotubes

A suggestion for substitutional Si doping in single-wall carbon nanotubes (SWNTs) through radial tube deformation is presented. Although the doping of buckyballs with substitutional Si atoms has been experimentally achieved, so far the synthesis of silicon-doped SWNT has not been reported. Using theoretical methods based on first-principles, the formation energies for Si doping on deformed (10,0) SWNTs are calculated, and their electronic and structural properties are investigated. It is established that, upon tube compression, the formation energy for Si doping in the large curvature region of the SWNT is reduced to values similar to the ones obtained for Si in buckyballs, indicating that this procedure may help to surmount the experimental difficulties associated with Si doping of SWNTs.