Novel transport properties of gold-single wall carbon nanotubes composite contacts

Using the density functional theory and nonequilibrium Green's function method, we report the effect of the gold-single wall carbon nanotubes (SWCNTs) composite contacts on the electronic structures and the transport properties of the device constructed by SWCNTs [SWCNT(10,0) or SWCNT(5,5)] and gold electrodes. The transmissions of the devices are greatly improved due to the strong couplings between carbon and gold atoms of the composite contacts. As for SWCNT(10,0), the gold atoms in the composite contacts behave as n-type dopant and depress the Schottky barrier between SWCNT(10,0) and the gold electrode. Moreover, the negative differential resistance characteristics occurs in the devices constructed by gold-SWCNT(10,0) composite contacts. c 2010 American Institute of Physics. [doi:10.1063/1.3483246]