US Patent 7687801 - CNT dopant material

http://www.freepatentsonline.com/7687801.html

This patent teaches dopants for carbon nanotube transistors enabling better control of the gate threshold voltage. Claim 1 reads:

1. A semiconductor device comprising, as the device,

a semiconductor material that is obtained by depositing, on a carbon nanotube, a donor with a smaller ionization potential than an intrinsic work function of the carbon nanotube or an acceptor with a larger electron affinity than the intrinsic work function of the carbon nanotube, wherein the ionization potential of the donor in vacuum is 6.4 eV or less.