Methods for production of single-crystal graphenes
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.
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.