Method Of Pulsed Laser-Based Large Area Graphene Synthesis On Metallic And Crystalline Substrates

Patent metadata

Field	Value
Publication number	US-2016340797-A1
Application number	US-201515116364-A
Country	US
Kind code	A1
Filing date	Feb 4, 2015
Priority date	Feb 4, 2014
Publication date	Nov 24, 2016
Grant date	—

Abstract

A method of making graphene includes providing a seed gas in the presence of a metallic substrate, providing a pulsed, ultraviolet laser beam, and moving the substrate or the laser beam relative to the other, thereby advancing a graphene crystallization front and forming an ordered graphene structure. In some instances, the substrate can have a surface with two-fold atomic symmetry. A method of recrystallizing graphene includes providing a pulsed, ultraviolet laser beam to a polycrystalline graphene sheet.

First claim

What is claimed is:

1 . A method of making graphene, comprising:
providing a seed gas in the presence of a metallic substrate; providing a pulsed, ultraviolet laser beam to photodissociate the seed gas; and moving the substrate or the ultraviolet laser beam relative to the other, thereby advancing a graphene crystallization front and forming an ordered graphene structure.

2 . (canceled)

3 . The method of claim 1 , wherein the ultraviolet laser beam has a pulse duration of about 10 nanoseconds.

4 . The method of claim 1 , wherein the ultraviolet laser beam is substantially parallel to the surface of the substrate and near the surface of the substrate.

5 . The method of claim 4 , wherein the ultraviolet laser beam is about 5 centimeters or less from the substrate.

6 . The method of claim 1 , wherein the ultraviolet laser beam contacts the substrate at an angle of about 30 degrees or less.

7 . The method of claim 1 , wherein the seed gas is methane or acetylene.

8 . The method of claim 1 , wherein the wavelength of the ultraviolet laser beam is approximately 193 nm, 248 nm, or 308 nm.

9 . The method of claim 1 , wherein the metallic substrate is nickel, copper, scandium, titanium, vanadium, manganese, iron, cobalt, ruthenium, platinum, germanium, silicon carbide, silicon, or a copper-nickel alloy.

10 . The method of claim 9 , wherein the substrate has a two-fold symmetric atomic surface.

11 . The method of claim 10 , wherein the substrate has a germanium [110] surface.

12 . The method of claim 11 , further comprising preparing the germanium [110] surface by contacting the germanium [110] surface with one or more of piranha solution (H 2 O 2 :H 2 SO 4 ) and hydrofluoric acid.

13 . The method of claim 10 , wherein the substrate has a silicon [110] surface.

14 . The method of claim 1 , further comprising annealing the ordered graphene structure with the laser.

15 . A method of recrystallizing graphene, comprising:
a) providing a pulsed, ultraviolet laser beam to a polycrystalline graphene sheet; and b) moving the substrate or the ultraviolet laser beam relative to the other, thereby causing the graphene to become more crystalline.

16 . The method of claim 15 , wherein the laser beam has a pulse duration of about 10 nanoseconds.

17 . The method of claim 15 , wherein the wavelength of the laser is approximately 193 nm, 248 nm, or 308 nm.

Assignees

• Nat Univ Singapore

Inventors

• Ozyilmaz Barbaros
• Stier Andreas Volker
• Toh Chee Tat
• Castro Neto Antonio Helio

Classifications

• C01B2204/32

  Size or surface area · CPC title

• C30B25/105 Primary

  by irradiation or electric discharge · CPC title

• C01B32/188

  by epitaxial growth · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01B32/186 Primary

  by chemical vapour deposition [CVD] · CPC title