Investigation of Metal-Induced Enhancement in Electrical Conductance of Multiwalled Carbon Nanotubes

We here segregate the contributions of contact improvement and change in multiwalled carbon nanotube´s (MWNT) inherent properties in electrical conductance enhancement caused by metal deposition. The conductance of individual MWNTs enhances greatly due to the platinum and tungsten deposition even at the locations of the tube where no beneath metal contact is present. The change in conductance is explained in terms of the change in the density of states at Fermi level, due to charge transfer between metal atoms and nanotube as well as by radial stress created on the tube. This type of improved conduction is different from the high bias-assisted tunneling type carrier transport and in our study, even at zero bias an increment of 140% in the typical conductance value has been experimentally observed. These results are important for electronic device perspective of nanowire research, mainly the interconnect applications in real electronic devices.