Epitaxial base

1. An epitaxial base, comprising:

a substrate comprising an epitaxial growth surface;

a plurality of bulges located on the epitaxial growth surface and defining a plurality of grooves; and

a carbon nanotube layer located on the epitaxial growth surface, wherein a first part of the carbon nanotube layer is attached to top surfaces of the plurality of bulges, a second part of the carbon nanotube layer is attached to bottom surfaces of the plurality of grooves, the second part of the carbon nanotube layer is separated from the first part of the carbon nanotube layer, and side surfaces of the plurality of grooves are free of carbon nanotubes.

2. The epitaxial base of claim 1 , wherein each of the plurality of grooves is bar-shaped and the plurality of grooves are intersected with each other to form a patterned surface.

3. The epitaxial base of claim 1 , wherein each of the plurality of grooves is bar-shaped and extends along a first direction; and the carbon nanotube layer comprises a plurality of carbon nanotubes extending along a second direction perpendicular to the first direction.

4. The epitaxial base of claim 3 , wherein a width of each of the plurality of grooves ranges from about 1 micrometer to about 50 micrometers, a depth of each of the plurality of grooves ranges from about 0.1 micrometers to about 1 micrometer, and an interval between adjacent two of the plurality of grooves ranges from about 1 micrometer to about 20 micrometers.

5. The epitaxial base of claim 1 , wherein each of the plurality of bulges is bar-shaped and the plurality of bulges are parallel with each other or intersected with each other.

6. The epitaxial base of claim 1 , wherein each of the plurality of bulges is dot-shaped and disperses on the epitaxial growth surface.

7. The epitaxial base of claim 1 , wherein the carbon nanotube layer is a free-standing and continuous structure.

8. The epitaxial base of claim 7 , wherein the carbon nanotube layer comprises a carbon nanotube film comprising a plurality of carbon nanotube segments successively oriented and serially joined end-to-end.

9. The epitaxial base of claim 7 , wherein the carbon nanotube layer comprises a plurality of carbon nanotubes arranged parallel with each other.

10. The epitaxial base of claim 1 , wherein the first part of the carbon nanotube layer comprises a plurality of first carbon nanotubes in direct contact with and parallel to the top surfaces, and the second part of the carbon nanotube layer comprises a plurality of second carbon nanotubes in direct contact with and parallel to the bottom surfaces.

11. The epitaxial base of claim 1 , wherein the carbon nanotube layer defines a plurality of apertures, and the epitaxial growth surface is partially exposed through the plurality of apertures.

12. The epitaxial base of claim 11 , wherein a size of each of the plurality of apertures ranges from about 10 nanometers to about 10 micrometers.

13. The epitaxial base of claim 1 , wherein the substrate is a single-crystal structure, and the carbon nanotube layer comprises a plurality of carbon nanotubes extending along a crystallographic orientation of the single-crystal structure.

14. The epitaxial base of claim 1 , wherein the plurality of bulges is selected from the group consisting of silicon dioxide, silicon nitride, silicon oxynitride, and titanium dioxide.

15. The epitaxial base of claim 1 , wherein the substrate is selected from the group consisting of LiGaO 2 , LiAlO 2 , Al 2 O 3 , Si, GaAs, GaN, GaSb, InN, InP, InAs, InSb, AlP, AlAs, AlSb, AlN, GaP, SiC, SiGe, GaMnAs, GaAlAs, GaInAs, GaAlN, GaInN, AlInN, GaAsP, InGaN, AlGaInN, AlGaInP, GaP:Zn and GaP:N.

16. An epitaxial base, comprising:

a substrate comprising an epitaxial growth surface and defining a plurality of grooves and a plurality of bulges on the epitaxial growth surface; and

a carbon nanotube layer located on the epitaxial growth surface, wherein a first part of the carbon nanotube layer is attached to top surfaces of the plurality of bulges, a second part of the carbon nanotube layer is attached to bottom surfaces of the plurality of grooves, the second part of the carbon nanotube layer is separated from the first part of the carbon nanotube layer, and side surfaces of the plurality of grooves are free of carbon nanotubes.

17. The epitaxial base of claim 16 , wherein the first part of the carbon nanotube layer comprises a plurality of first carbon nanotubes in direct contact with and parallel to the top surfaces, and the second part of the carbon nanotube layer comprises a plurality of second carbon nanotubes in direct contact with and parallel to the bottom surfaces.

18. The epitaxial base of claim 16 , wherein the carbon nanotube layer is a free-standing structure.

19. An epitaxial base, comprising:

a substrate comprising an epitaxial growth surface and defining a plurality of grooves and a plurality of bulges on the epitaxial growth surface;

a first carbon nanotube layer located on top surfaces of the plurality of bulges; and

a second carbon nanotube layer located on bottom surfaces of the plurality of grooves, wherein the second carbon nanotube layer is spaced from the first carbon nanotube layer and not connected by any other carbon nanotubes.

20. The epitaxial base of claim 19 , wherein the first carbon nanotube layer comprises a plurality of first carbon nanotubes in direct contact with and parallel to the top surfaces, and the second carbon nanotube layer comprises a plurality of second carbon nanotubes in direct contact with and parallel to the bottom surfaces.