Method of making nanotube-based material with enhanced electron field emission properties
AssigneeThe University of North Carolina at Chapel Hill
InventorOtto Z. Zhou
Life of this patent
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Abstract
A method of reducing electronic work function, reducing threshold field emission values, converting semiconducting behavior to metallic behavior, increasing the electron density state at the Fermi level, and increasing electron emission site density, of nanostructure or nanotube-containing material, the method including: forming openings in the nanotube-containing material; introducing a foreign species such as an alkali metal into at least some of the openings; and closing the openings, thereby forming capsules filled with the foreign species, and forming field emission cathode and flat panel displays using these capsules.
Claims54
A method of manufacturing a material comprising:
- (a) producing raw nanostructure or nanotube-containing material comprising closed structures;
- (b) purifying the raw material;
- (c) processing the purified material thereby forming openings in the closed structures;
- (d) introducing a foreign species comprising electron donors or electron acceptors into at least some of the openings;
- (e) varying at least one of electronic work function, electronic density of state at the Fermi Level, and electrical conductivity of the material by controlling the amount of foreign species introduced at step (d);
- and
- (f) closing the openings by forming passivation layers, the passivation layers being formed by exposing the nanostructure or nanotube-containing material containing the foreign species to oxygen or an oxygen-containing gas, thereby forming capsules filled with the foreign species.
A method of manufacture comprising:
- (a) producing vertically oriented carbon nanotubes on a support surface;
- (b) applying an insulating layer;
- (c) opening tops of the nanotubes;
- (d) introducing a foreign species into the open tops and into interior spaces of the nanotubes;
- (e) closing the open tops of the nanotubes;
- and
- (f) activating the filled nanotubes.
Dependencies are inferred from the claim text.