US Patent 8221715 - N-doping CNT material

http://www.freepatentsonline.com/8221715.html

Carbon nanotubes are usually in the p-doped state after being prepared because electron depletion occurs due to the use of an acid for the removal of the metal catalysts used in growing the nanotubes. This patent from Samsung teaches a method for n-doping the nanotubes using reducing agents and thus enables the creation of bipolar electronics from nanotubes. Claim 1 reads:

1. A method for n-doping of carbon nano-tubes comprising:

n-doping carbon nano-tubes with a carbon nano-tube n-doping material comprising a compound containing at least two pyridinium derivatives in its molecular structure, the compound being in a reduced form thereof.