The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 17, 2009
Filed:
Dec. 16, 2004
Jie Liu, Chapel Hill, NC (US);
Chunsheng Du, Davis, CA (US);
Cheng Qian, Durham, NC (US);
BO Gao, Elon, NC (US);
Qi Qiu, Cary, NC (US);
Otto Z. Zhou, Chapel Hill, NC (US);
Jie Liu, Chapel Hill, NC (US);
Chunsheng Du, Davis, CA (US);
Cheng Qian, Durham, NC (US);
Bo Gao, Elon, NC (US);
Qi Qiu, Cary, NC (US);
Otto Z. Zhou, Chapel Hill, NC (US);
Duke University, Durhan, NC (US);
Xintek, Inc., Research Triangle Park, NC (US);
Abstract
Carbon nanotube material having an outer diameter less than 10 nm and a number of walls less than ten are disclosed. Also disclosed are an electron field emission device including a substrate, an optionally layer of adhesion-promoting layer, and a layer of electron field emission material. The electron field emission material includes a carbon nanotube having a number of concentric graphene shells per tube of from two to ten, an outer diameter from 2 to 8 nm, and a nanotube length greater than 0.1 microns. One method to fabricate carbon nanotubes includes the steps of (a) producing a catalyst containing Fe and Mo supported on MgO powder, (b) using a mixture of hydrogen and carbon containing gas as precursors, and (c) heating the catalyst to a temperature above 950° C. to produce a carbon nanotube. Another method of fabricating an electron field emission cathode includes the steps of (a) synthesizing electron field emission materials containing carbon nanotubes with a number of concentric graphene shells per tube from two to ten, an outer diameter of from 2 to 8 nm, and a length greater than 0.1 microns, (b) dispersing the electron field emission material in a suitable solvent, (c) depositing the electron field emission materials onto a substrate, and (d) annealing the substrate.