Method of synthesizing small-diameter carbon nanotubes with electron field emission properties
US7618300B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 16, 2004 |
| Grant date | Nov 17, 2009 |
| Priority date | — |
| Expiry date | Dec 16, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2201/30469
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
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) …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.