Methods for production of single-crystal graphenes

Patent metadata

Field	Value
Publication number	US-9845551-B2
Application number	US-201313939086-A
Country	US
Kind code	B2
Filing date	Jul 10, 2013
Priority date	Jul 10, 2012
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

In some embodiments, the present disclosure pertains to methods of forming single-crystal graphenes by: (1) cleaning a surface of a catalyst; (2) annealing the surface of the catalyst; (3) applying a carbon source to the surface of the catalyst; and (4) growing single-crystal graphene on the surface of the catalyst from the carbon source. Further embodiments of the present disclosure also include a step of separating the formed single-crystal graphene from the surface of the catalyst. In some embodiments, the methods of the present disclosure also include a step of transferring the formed single-crystal graphene to a substrate. Additional embodiments of the present disclosure also include a step of growing stacks of single crystals of graphene.

First claim

What is claimed is:

1. A method of forming large-size single-crystal graphene, wherein the method comprises:
cleaning a surface of a catalyst;
annealing the surface of the cleaned catalyst, wherein the annealing occurs at pressures of 1,000 Torr or higher;
applying a carbon source to the surface of the catalyst; and
growing single-crystal graphene on the surface of the catalyst,
wherein the formed single-crystal graphene has a width that ranges from 1 mm to 5 meters.

2. The method of claim 1 , wherein the catalyst is selected from the group consisting of Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V and Zr, mixtures thereof, and combinations thereof.

3. The method of claim 1 , wherein the catalyst is a copper foil.

4. The method of claim 1 , wherein the catalyst is in polycrystalline form.

5. The method of claim 1 , wherein the cleaning comprises electrochemical-polishing the surface of the catalyst.

6. The method of claim 1 , wherein the annealing comprises thermal annealing.

7. The method of claim 6 , wherein the thermal annealing occurs at temperatures of 500° C. or higher.

8. The method of claim 6 , wherein the thermal annealing occurs at pressures of 1,500 Torr or higher.

9. The method of claim 6 , wherein the thermal annealing occurs in a reductive environment comprising a stream of a reductive gas.

10. The method of claim 9 , wherein the reductive gas is hydrogen.

11. The method of claim 1 , wherein the applying of the carbon source occurs by chemical vapor deposition.

12. The method of claim 1 , wherein the carbon source is selected from the group consisting of hydrocarbons, polymers, non-polymeric carbon sources, small molecules, organic compounds, fullerenes, fluorenes, carbon nanotubes, phenylene, ethylenes, sucrose, sugars, polysaccharides, carbohydrates, proteins, and combinations thereof.

13. The method of claim 1 , wherein the carbon source is a hydrocarbon.

14. The method of claim 13 , wherein the hydrocarbon is methane.

15. The method of claim 1 , wherein the growing occurs at temperatures of 500° C. or higher.

16. The method of claim 1 , wherein the growing occurs at a pressure of between 100 Torr and 110 Torr.

17. The method of claim 1 , wherein the growing occurs for 2 hours or longer.

18. The method of claim 1 , wherein the growing occurs in a reductive environment comprising a stream of a reductive gas.

19. The method of claim 18 , wherein the reductive gas is hydrogen.

20. The method of claim 1 , further comprising a step of controlling the morphology of the single-crystal graphene by adjusting various growth parameters.

21. The method of claim 20 , wherein the growth parameters comprise flow rate of a reductive gas during growth, growth time, growth temperature, annealing temperature, growth pressure, type of catalyst, and combinations thereof.

22. The method of claim 1 , further comprising a step of separating the formed single-crystal graphene from the surface of the catalyst.

23. The method of claim 1 , further comprising a step of transferring the formed single-crystal graphene to a substrate.

24. The method of claim 1 , wherein the method occurs without the use of a vacuum.

25. The method of claim 1 , wherein the method occurs under positive pressure.

26. A method of forming large-size and stacked layers of single crystals of graphene, wherein the method comprises:
cleaning a surface of a catalyst;
annealing the surface of the cleaned catalyst, wherein the annealing occurs at pressures of 1,000 Torr or higher;
applying a carbon source to the surface of the catalyst; and
growing stacked layers of single crystals of graphene on the surface of the catalyst,
wherein the single crystals of graphene comprise widths that range from 1 mm to 5 meters.

27. The method of claim 26 , wherein the stacked layers of single crystals of graphene comprise a bilayer.

28. The method of claim 26 , wherein the stacked layers of single crystals of graphene comprise a trilayer.

29. The method of claim 26 , wherein the stacked layers of single crystals of graphene form by repeating the applying and growing steps until a desired number of stacked layers of single crystals of graphene are formed.

30. The method of claim 26 , wherein the catalyst is selected from the group consisting of Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V and Zr, mixtures thereof, and combinations thereof.

31. The method of claim 26 , wherein the catalyst is a copper foil.

32. The method of claim 26 , wherein the cleaning comprises electrochemical-polishing the surface of the catalyst.

33. The method of claim 26 , wherein the annealing comprises thermal annealing.

34. The method of claim 33 , wherein the thermal annealing occurs at temperatures of 500° C. or higher and pressures of 1,500 Torr or higher.

35. The method of claim 33 , wherein the thermal annealing occurs in a reductive environment comprising a stream of a reductive gas.

36. The method of claim 26 , wherein the applying of the carbon source occurs by chemical vapor deposition.

37. The method of claim 26 , wherein the carbon source is a hydrocarbon.

38. The method of claim 26 , wherein the growing occurs at temperatures of 500° C. or higher and pressures of 100 Torr or higher.

39. The method of claim 26 , wherein the growing occurs in a reductive environment comprising a stream of a reductive gas.

40. The method of claim 26 , further comprising a step of controlling the morphologies of the single crystals of graphene by adjusting various growth parameters.

41. The method of claim 40 , wherein the growth parameters comprise flow rate of a reductive gas during growth, growth time, growth temperature, annealing temperature, growth pressure, type of catalyst, and combinations thereof.

42. The method of claim 26 , further comprising a step of separating the formed single crystals of graphene from the surface of the catalyst.

43. The method of claim 26 , further comprising a step of transferring the formed single crystals of graphene to a substrate.

44. The method of claim 1 , wherein the growing occurs at pressures below 760 Torr.

45. The method of claim 26 , wherein the growing occurs at pressures below 760 Torr.

Assignees

• Tour James M
• Yan Zheng
• Univ Rice William M

Inventors

• Tour James M
• Yan Zheng

Classifications

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C30B25/02

  Epitaxial-layer growth · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C30B25/186 Primary

  being specially pre-treated by, e.g. chemical or physical means · CPC title

• C30B29/02

  Elements · CPC title