Patent ID: 7585199

Claim:
A method for making a field emission cathode comprising the steps of: dispersing carbon nanotubes into a liquid vehicle to form a suspension, said carbon nanotubes being substantially cylindrical carbon fibrils having one or more graphitic layer concentric with their cylindrical axes, and said carbon fibrils being substantially free of pyrolytically deposited carbon overcoat, having a substantially uniform diameter between 1 nm and 100 nm and having a length to diameter ratio greater than 5; forming an electrophoresis bath, said bath including an anode and a cathode immersed therein; applying a voltage to said anode and said cathode, thereby causing said carbon nanotubes to deposit onto said cathode; removing said cathode from said bath; heating said cathode; and bombarding said cathode with gallium or carbon ions without concurrently or subsequently oxidizing said carbon nanotubes in said cathode.