Thermally and electrically conductive structure comprising a carbon nanotube, a graphite sheet and a metal layer; and method of reducing a contact resistance of same
View Patent ↗A thermally and electrically conductive structure comprises a carbon nanotube ( 110 ) having an outer surface ( 111 ) and a carbon coating ( 120 ) covering at least a portion of the outer surface of the carbon nanotube. The carbon coating may be applied to the carbon nanotube by providing a nitrile-containing polymer, coating the carbon nanotube with the nitrile-containing polymer, and pyrolyzing the nitrile-containing polymer in order to form the carbon coating on the carbon nanotube. The carbon nanotube may further be coated with a low contact resistance layer ( 130 ) exterior to the carbon coating and a metal layer ( 140 ) exterior to the low contact resistance layer.
1. A thermally and electrically conductive structure comprising:
a carbon nanotube having an outer surface;
a first transition layer, comprising a graphite sheet, covering at least a portion of the outer surface of the carbon nanotube;
a second transition layer exterior to the first transition layer; and
a metal layer exterior to the second transition layer.
2. The thermally and electrically conductive structure of claim 1 wherein:
the first transition layer surrounds substantially all of the outer surface of the carbon nanotube.
3. The thermally and electrically conductive structure of claim 1 wherein:
the first transition layer provides the thermally and electrically conductive structure with a reactive surface.
4. The thermally and electrically conductive structure of claim 1 wherein:
the second transition layer is a low contact resistance layer.
5. The thermally and electrically conductive structure of claim 1 wherein:
the second transition layer comprises a metal or a polymer.
6. The thermally and electrically conductive structure of claim 5 wherein:
the second transition layer comprises one of copper, nickel, ruthenium, and platinum.
7. The thermally and electrically conductive structure of claim 1 wherein:
the first transition layer is derived from a nitrile-containing polymer.
8. A method of reducing a contact resistance of a carbon nanotube, the method comprising:
providing a nitrile-containing polymer;
coating the carbon nanotube with the nitrile-containing polymer;
pyrolyzing the nitrile-containing polymer in order to form a first transition layer, comprising a graphite sheet, on the carbon nanotube;
forming a low contact resistance layer exterior to the first transition layer; and
forming a metal layer exterior to the low contact resistance layer.
9. The method of claim 8 further comprising:
performing an acid treatment on the carbon nanotube.
10. The method of claim 9 wherein:
pyrolyzing the nitrile-containing polymer comprises pyrolyzing the nitrile-containing polymer in a tube furnace at a temperature of not more than approximately 700 degrees Celsius for approximately six hours in argon.
11. A thermally and electrically conductive structure comprising:
a carbon nanotube having an outer surface;
a first transition layer, comprising a graphite sheet, in physical contact with the outer surface of the carbon nanotube;
a second transition layer in physical contact with the first transition layer; and
a metal layer in physical contact with the second transition layer.
12. The thermally and electrically conductive structure of claim 11 wherein:
the first transition layer has a lattice parameter that causes a reduction in thermal interface resistance across the outer surface of the carbon nanotube.
13. The thermally and electrically conductive structure of claim 11 wherein:
the first transition layer provides the thermally and electrically conductive structure with a reactive surface.
14. The thermally and electrically conductive structure of claim 11 wherein:
the first transition layer is derived from a nitrile-containing polymer.