Multilayer graphene, method of forming the same, device including the multilayer graphene, and method of manufacturing the device
A multilayer graphene, a method of forming the same, a device including the multilayer graphene, and a method of manufacturing the device are provided. In the method of forming the multilayer graphene, a first graphene is formed on an underlayer, and then a multilayer graphene is formed by exposing two adjacent areas on the first graphene to a source gas. By differentiating temperatures and source gasses, the multilayer graphene has different electrical characteristics in the two adjacent areas.
1. A method of forming a multilayer graphene, the method comprising:
forming a first graphene on an underlayer;
forming a first multilayer graphene on a first area of the first graphene at a first temperature by using a first source gas, the first multilayer graphene comprising a portion of the first graphene corresponding to the first area; and
forming a second multilayer graphene on a second area of the first graphene adjacent to the first area at a second temperature by using a second source gas, the second multilayer graphene comprising a portion of the first graphene corresponding to the second area,
wherein the first temperature is different from the second temperature.
2. The method of claim 1 , wherein the first graphene is a monolayer graphene.
3. The method of claim 2 , wherein at least one of the first multilayer graphene and the second multilayer graphene is a bilayer graphene.
4. The method of claim 1 , wherein one of the first multilayer graphene and the second multilayer graphene is a p-type multilayer graphene and the other one of the first multilayer graphene and the second multilayer graphene is an n-type multilayer graphene, and
the first multilayer graphene and the second multilayer graphene form a pn junction.
5. The method of claim 1 , wherein the first source gas is the same as the second source gas.
6. The method of claim 5 , wherein each of the first source gas and the second source gas comprises a nitrogen (N)-containing hydrocarbon compound.
7. The method of claim 6 , wherein the N-containing hydrocarbon compound comprises pyridine (C 5 H 5 N).
8. The method of claim 6 , wherein the first temperature is about 700° C. or greater, and
the second temperature is about 550° C. or less.
9. The method of claim 8 , wherein the first graphene is formed at the first temperature by using the first source gas.
10. The method of claim 8 , wherein the first multilayer graphene is a p-type multilayer graphene, and
the second multilayer graphene is an n-type multilayer graphene.
11. The method of claim 4 , wherein the first multilayer graphene is formed as the p-type multilayer graphene due to a doping effect of the underlayer, and
the second multilayer graphene is formed as the n-type multilayer graphene due to an n-type dopant included in the second source gas.
12. The method of claim 1 , wherein the first source gas is different from the second source gas.
13. The method of claim 12 , wherein one of the first source gas and the second source gas comprises a first hydrocarbon compound and the other one of the first source gas and the second source gas comprises a second hydrocarbon compound, and
the first hydrocarbon compound does not contain N, and the second hydrocarbon compound contains N.
14. The method of claim 4 , further comprising forming a third multilayer graphene joined to the first multilayer graphene or the second multilayer graphene,
wherein the third multilayer graphene is a p-type multilayer graphene or an n-type multilayer graphene.
15. The method of claim 14 , wherein each of the first through third multilayer graphenes has a pnp or npn structure.
16. The method of claim 1 , wherein the first multilayer graphene and the second multilayer graphene are both of a p-type conductive type or an n-type conductive type and have doping concentrations different from each other.
17. The method of claim 16 , wherein the first source gas is the same as the second source gas.
18. The method of claim 17 , wherein each of the first source gas and the second source gas comprises an N-containing hydrocarbon compound.
19. The method of claim 18 , wherein the N-containing hydrocarbon compound comprises pyridine (C 5 H 5 N).
20. The method of claim 18 , wherein the first temperature is about 550° C. to about 800° C., and
the second temperature is about 550° C. or less.
21. The method of claim 20 , wherein the first graphene is formed at the first temperature by using the first source gas.
22. The method of claim 18 , wherein the first multilayer graphene is an n-type multilayer graphene, and
the second multilayer graphene is an n+-type multilayer graphene.
23. The method of claim 1 , wherein the first multilayer graphene is formed using a first mask that exposes the first area of the first graphene, and
the second multilayer graphene is formed using a second mask that exposes the second area of the first graphene.
24. The method of claim 1 , wherein the first and second multilayer graphenes are randomly distributed.
25. The method of claim 1 , wherein the underlayer comprises a catalyst metal.
26. The method of claim 25 , wherein the catalyst metal comprises platinum (Pt) or gold (Au).
27. The method of claim 1 , further comprising forming the underlayer by forming a first material layer on a substrate, and forming a plurality of underlayers spaced apart from one another by patterning the first material layer.
28. A method of forming a multilayer graphene, the method comprising:
forming a first graphene on an underlayer;
forming a first multilayer graphene on a first area of the first graphene at a first temperature by using a first source gas, the first multilayer graphene comprising a portion of the first graphene corresponding to the first area; and
forming a second multilayer graphene on a second area of the first graphene adjacent to the first area at a second temperature by using a second source gas, the second multilayer graphene comprising a portion of the first graphene corresponding to the second area,
wherein the first source gas is different from the second source gas.
29. The method of claim 28 , wherein the first graphene is a monolayer graphene.
30. The method of claim 29 , wherein at least one of the first multilayer graphene and the second multilayer graphene is a bilayer graphene.
31. The method of claim 28 , wherein one of the first source gas and the second source gas comprises a first hydrocarbon compound and the other one of the first source gas and the second source gas comprises a second hydrocarbon compound, and
the first hydrocarbon compound does not contain nitrogen (N), and the second hydrocarbon compound contains N.
32. The method of claim 31 , wherein the first multilayer graphene is formed as a p-type multilayer graphene by the first hydrocarbon compound, and
the second multilayer graphene is formed as an n-type multilayer graphene by the second hydrocarbon compound.
33. The method of claim 32 , wherein the first hydrocarbon compound comprises at least one of benzene (C 6 H 6 ), ethylene (C 2 H 4 ), acetylene (C 2 H 2 ), and triethylborane (C 6 H 15 B).
34. The method of claim 32 , wherein the first hydrocarbon compound contains boron (B).
35. The method of claim 32 , wherein the second hydrocarbon compound comprises pyridine (C 6 H 5 N).
36. The method of claim 31 , wherein the first graphene is formed using the first hydrocarbon compound.
37. A method of forming a multilayer graphene, the method comprising:
forming a first graphene on an underlayer; and
forming a multilayer graphene on a first area of the first graphene at a first temperature by using a first source gas, the multilayer graphene comprising a portion of the first graphene corresponding to the first area,
wherein a temperature used to form the first graphene is different from the first temperature, or a source gas used to form the first graphene is different from the first source gas.
38. The method of claim 37 , wherein the multilayer graphene is a bilayer graphene.
39. The method of claim 37 , wherein one of the first graphene and the multilayer graphene is a p-type multilayer graphene and the other one of the first graphene and the multilayer graphene is an n-type multilayer graphene, and
the first graphene and the multilayer graphene form a pn junction.
40. A method of manufacturing a graphene-containing device, the method comprising:
forming a first graphene on an underlayer;
forming a first multilayer graphene on a first area of the first graphene at a first temperature by using a first source gas, the first multilayer graphene comprising a portion of the first graphene corresponding to the first area;
forming a second multilayer graphene on a second area of the first graphene adjacent to the first area at a second temperature by using a second source gas, the second multilayer graphene comprising a portion of the first graphene corresponding to the second area; and
forming a device unit comprising the multilayer graphene,
wherein the first temperature is different from the second temperature.
41. The method of claim 40 , wherein the multilayer graphene is formed on a first substrate, and
the device unit is formed on the second substrate after the multilayer graphene has been transferred from the first substrate to a second substrate.
42. The method of claim 40 , wherein the multilayer graphene is formed on a first substrate, and
the device unit is formed on the first substrate.
43. A graphene-containing device comprising a multilayer graphene formed by using a method comprising:
forming a first graphene on an underlayer;
forming a first multilayer graphene on a first area of the first graphene at a first temperature by using a first source gas, the first multilayer graphene comprising a portion of the first graphene corresponding to the first area; and
forming a second multilayer graphene on a second area of the first graphene adjacent to the first area at a second temperature by using a second source gas, the second multilayer graphene comprising a portion of the first graphene corresponding to the second area,
wherein the first temperature is different from the second temperature.
44. The graphene-containing device of claim 43 , wherein the graphene-containing device is a diode, and
the graphene-containing device comprises a first electrode connected to the first multilayer graphene and a second electrode connected to the second multilayer graphene.
45. The graphene-containing device of claim 43 , wherein the graphene-containing device is a transistor, and
the multilayer graphene is a channel layer.
46. The graphene-containing device of claim 45 , wherein the multilayer graphene has a pnp or npn structure.
47. The graphene-containing device of claim 43 , wherein the graphene-containing device comprises one of a tunneling device, a binary junction transistor (BJT), a barristor, a field effect transistor (FET), a memory device, a solar cell, a photodetector, a sensor, and a light-emitting device.
48. A graphene device comprising a multilayer graphene, the multilayer graphene comprising:
an n-type multilayer graphene formed on a first area; and
a p-type multilayer graphene formed on a second area adjacent to the first area,
wherein the n-type multilayer graphene has a crystal structure in which some of carbon (C) atoms are replaced by first atoms, and
the p-type multilayer graphene has a crystal structure including only C atoms or has a crystal structure in which a plurality of C atoms are replaced by second atoms different from the first atoms.
49. The graphene device of claim 48 , wherein the multilayer graphene is a bilayer graphene.
50. The graphene device of claim 48 , wherein the first atoms are N atoms.
51. A method of forming a defect-free junction between edge portions of graphene sheets comprising:
forming a first graphene on an underlayer;
forming a second graphene between the first graphene and the underlayer by exposing a first area of the first graphene to a first temperature above about 450° C. and a first source gas comprising a hydrocarbon compound;
forming a third graphene between the first graphene and the underlayer by exposing a second area of the first graphene to a second temperature above about 450° C. and a second source gas comprising a hydrocarbon compound,
wherein the third graphene is in direct contact with an edge portion of the second graphene, and
wherein the second area of the first graphene does not include any of the first area of the first graphene.