Method for transferring a large-area graphene sheet

Patent metadata

Field	Value
Publication number	US-9962914-B2
Application number	US-201615002440-A
Country	US
Kind code	B2
Filing date	Jan 21, 2016
Priority date	Jan 21, 2016
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A method of transferring a graphene sheet comprising one or more layers of graphene formed on a metal film, such as a copper film, coating a surface of a metal or alloy substrate onto a target substrate. The method includes fixedly contacting the graphene sheet with a contacting surface of the target substrate by applying substantially uniform pressure and heat on a layered assembly. The layered assembly comprises the metal or alloy substrate, the graphene sheet, and the target substrate. At least one layer of graphene of the graphene sheet formed on the copper film coating the surface of the metal or alloy substrate is transferred onto the contacting surface of the target substrate by the substantially uniform pressure and heat, and the at least one layer of graphene forms a graphene film on the contacting surface of the target substrate.

First claim

The invention claimed is:

1. A method for transferring a graphene layer on a first substrate onto a second target substrate, comprising:
contacting a graphene layer on the first substrate, which comprises one or more layers of graphene formed on a copper film that is formed on a surface of a metal foil, with a contacting surface of the second target substrate under substantially uniform pressure and heat, thereby transferring the at least one graphene layer from the first substrate onto the contacting surface of the second target substrate;
wherein the thickness of the copper film that is formed on the surface of the metal foil of the first substrate is about 200-800 nm; and
wherein the transferring consists essentially of applying substantially uniform pressure and heat.

2. The method of claim 1 , wherein the thickness of the copper film that is formed on the surface of the metal foil of the first substrate is about 400-500 nm.

3. The method of claim 1 , wherein the metal foil of the first substrate is an alloy comprising Cu and at least one metal selected from the group consisting of silicon, Ni, Co, Fe, Pt, Au, Al, Cr, Ge, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V, and Zr.

4. The method of claim 1 , wherein the metal foil is a copper foil.

5. The method of claim 1 , further comprising growing the one or more graphene layers on the metal foil by contacting the foil with a reaction gas comprising carbon and with heat, thereby growing the one or more graphene layers on the foil.

6. The method of claim 1 , wherein the second target substrate comprises at least one selected from the group consisting of a polymer, a polymer mixture, a plastic, a rubber, a glass, a metal, Si, and SiO 2 .

7. The method of claim 1 , wherein the substantially uniform pressure is at least 5 psi.

8. The method of claim 1 , wherein the contacting of the graphene layer on the first substrate to the contacting surface of the second target substrate occurs at a temperature of at least 180° C.

9. A method of transferring a graphene layer on a first substrate onto a flexible second target substrate, comprising:
contacting a graphene layer on the first substrate, which comprises one or more layers of graphene formed on a copper film that is formed on a surface of a metal foil, with a contacting surface of the flexible second target substrate under substantially uniform pressure and heat, thereby transferring the at least one graphene layer from the first substrate onto the contacting surface of the flexible second target substrate, and
subjecting the flexible second target substrate to which the at least one graphene layer has been transferred to at least one blank page printing operation conducted by a printing device which comprises at least one fuser unit that comprises at least one heat roller and at least one pressure roller; wherein during the at least one blank page printing operation the at least one fuser unit applies substantially uniform pressure and heat on the flexible second target substrate to which the at least one graphene layer has been transferred via the at least one pressure roller and via the at least one heat roller;
wherein the thickness of the copper film coating the surface of the metal foil of the first substrate is about 200-800 nm; and
wherein the transferring consists essentially of applying substantially uniform pressure and heat.

10. The method of claim 9 , wherein the metal foil is etched to remove its surface prior to formation of the copper film on it.

11. The method of claim 9 , wherein the flexible second target substrate comprises at least one selected from the group consisting of polyethylene terephthalate, polyimide, cellulose acetate, glass, polyethylene naphthalate, polycarbonate, plastic, and rubber.

12. The method of claim 9 , wherein only one layer of graphene on the first substrate is transferred to the contacting surface of the flexible second substrate where it forms a monolayered graphene film.

13. The method of claim 12 , wherein the monolayered graphene film on the contacting surface of the flexible second target substrate has an optical transmittance of at least 88% when subjected to a light with a wavelength of 300-2000 nm.

14. The method of claim 9 , wherein the graphene film on the contacting surface of the flexible second target substrate has a resistance of no greater than 250 Ω/cm 2 by a four probe Van der Pauw method.

15. The method of claim 9 , further comprising stretching the graphene film on the contacting surface of the flexible second target substrate to form an elongated graphene film,
wherein the elongated graphene film has a dimension that is longer, but no greater than about 20% longer than the graphene film before the stretching, and
wherein the elongated graphene film has a resistance that is the same as, or different from, the resistance of the graphene film before the stretching, but no more than about 10% different from the resistance of the graphene film before the stretching.

16. The method of claim 9 , further comprising stretching the graphene film on the contacting surface of the flexible second target substrate to form an elongated graphene film,
wherein the elongated graphene film has a dimension that is longer, but no greater than 20% longer than the graphene film before the stretching, and then
relaxing the elongated graphene film from the stretching to form a relaxed graphene film,
wherein the relaxed graphene film has a resistance that is the same as, or different from, the resistance of the graphene film before the stretching, but no more than about 10% different from the resistance of the graphene film before the stretching.

17. The method of claim 9 , further comprising subjecting the graphene film on the contacting surface of the flexible second target substrate to a bending strain of no greater than about 30% to form a bent graphene film,
wherein the bent graphene film has a resistance that is the same as, or different from, the resistance of the graphene film before being subjected to the bending strain, but no more than about 10% different from the resistance of the graphene film before being subjected to the bending strain.

18. The method of claim 9 , further comprising subjecting the graphene film on the contacting surface of the flexible second target substrate to a bending strain of no greater than about 30% to form a bent graphene film, and then
relaxing the bent graphene film from the bending strain to form a relaxed graphene film,
wherein the relaxed graphene film has a resistance that is the same as, or different from, the resistance of the graphene film before being subjected to the bending strain, but no more than about 10% different from the resistance of the graphene film before being subjected to the bending strain.

19. The method of claim 1 , wherein the transferring consists essentially of applying substantially uniform pressure of at least 2 psi and heat of at least 150° C. and substantially uniform pressure and temperature vary by no more than 10% over the contacting surface of the second target substrate.

20. The method of claim 1 , wherein the transferring consists essentially of applying substantially uniform pressure of at least 10 psi and heat of at least 300° C. and substantially uniform pressure and temperature vary by no more than 1% over the contacting surface of the second target substrate.

Assignees

• Univ King Abdulaziz

Inventors

• Al-Hazmi Farag Saeed Marshoud
• Al-Ghamdi Ahmed Abdullah Salem
• ELSAYED Waleed Elsayed Mahmoud

Classifications

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• Y10T156/1956

  Roller pair delaminating means · CPC title

• Y10T428/30

  Self-sustaining carbon mass or layer with impregnant or other layer · CPC title

• C04B2237/363

  Carbon · CPC title

• B32B18/00

  Layered products essentially comprising ceramics, e.g. refractory products · CPC title