Plasmonic graphene and method of making the same
Plasmonic graphene is fabricated using thermally assisted self-assembly of plasmonic nanostructure on graphene. Silver nanostructures were deposited on graphene as an example.
1. A method for forming plasmonic graphene:
providing a graphene sheet on a support substrate;
forming a film of a plasmonic material on said graphene sheet;
heating at 500° C. or less said graphene sheet with said film of plasmonic material to form plasmonic graphene comprising graphene with plasmonic nanostructures thereon.
2. The method of claim 1 wherein said support substrate comprises a silicon dioxide or glass substrate.
3. The method of claim 1 wherein said providing step comprises the steps of growing a graphene sheet on a copper substrate using chemical vapor deposition; spin-coating a polymethylmethacrylate layer onto said graphene sheet; removing said copper substrate by contacting said copper substrate with an iron chloride solution; transferring said graphene to a silicon dioxide substrate; and removing said polymethylmethacrylate layer.
4. The method of claim 1 wherein said graphene sheet comprises 1 to 3 layers of graphene.
5. The method of claim 1 wherein said plasmonic material is selected from the group consisting of silver, gold, copper, or mixtures thereof.
6. The method of claim 1 wherein said film of plasmonic material has a thickness of about 4 to 10 nm.
7. The method of claim 1 further comprising the step of cleaning said graphene sheet prior to said plasmonic film forming step.
8. The method of claim 1 wherein said heating occurs at about 300° C. or less for about 5 to 60 minutes.
9. The method of claim 1 wherein said plasmonic material comprises silver and said plasmonic graphene comprises silver nanostructures on graphene.
10. The method of claim 9 wherein said nanostructures have an average dimension of about 50 to 150 nm.
11. The method of claim 9 wherein said nanostructures have an average height about 60 nm or less.
12. The method of claim 1 wherein said plasmonic graphene has an electrical conductivity that is higher than a graphene sheet without said plasmonic material.
13. The method of claim 1 wherein said plasmonic graphene exhibits a higher G peak and 2D peak compared to a graphene sheet without said plasmonic material.
14. The method of claim 1 wherein said plasmonic graphene exhibits a red-shifted plasmonic resonance frequency compared to said plasmonic material on bare glass.
15. The method of claim 1 wherein said plasmonic nanostructures are disk-like in shape.
16. The method of claim 1 wherein said plasmonic material is an electrically conductive material.
17. The method of claim 1 , wherein said heating occurs for 5 to 60 minutes.
18. The method of claim 1 wherein said heating occurs at 400° C. or less.
19. The method of claim 18 wherein said heating occurs at 300° C. or less.