Transparent electrodes from single wall carbon nanotubes

• US 20040197546A1
• Filed: 07/18/2003
• Published: 10/07/2004
• Est. Priority Date: 07/19/2002
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida (State University System of Florida)
• Inventors: Chen, Zhihong, Rinzler, Andrew G.
• Granted Patent: US 7,261,852 B2
• Time in Patent Office: Days
• US Class Current: 428/311.51
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/02 Single-walled nanotubes
• CPC Class Codes: C01B 2202/22 Electronic properties
• CPC Class Codes: C01B 32/168 After-treatment
• CPC Class Codes: D01F 9/12 Carbon filaments; Apparatus specially adapted for the manufacture thereof
• CPC Class Codes: H10K 30/821 comprising carbon nanotubes
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y10T 428/249964 Fibers of defined composition
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A method of forming optically transparent and electrically conductive SWNT films includes the steps of providing a porous membrane and dispersing a plurality of SWNTs into a solution, the solution including at least one surface stabilizing agent for preventing the SWNTs from flocculating out of suspension. The solution is then applied to the membrane. The solution is then removed, wherein the SWNTs are forced onto the surface of the porous membrane to form a SWNT film on the membrane. The method can include the step of separating the SWNT film from the porous membrane, such as by dissolving the membrane. An electrically conducting and optically transparent single wall carbon nanotube (SWNT) film provides a sheet resistance of less than 200 ohm/sq and at least 30% transmission at a wavelength of 3 μm.

Claims

1. A method of forming optically transparent and electrically conductive single walled carbon nanotubes (SWNT) films, comprising the steps of:

providing a porous membrane;

dispersing a plurality of single walled carbon nanotubes (SWNTs) into a solution, said solution including at least one surface stabilizing agent for preventing said SWNTs from flocculating out of suspension;

applying said solution to said membrane, and

removing said solution, wherein said SWNTs are forced onto a surface of said porous membrane to form a SWNT film disposed on said membrane.

2. The method of claim 1, further comprising the step of separating said SWNT film from said porous membrane.

3. The method of claim 2, wherein said separating step comprises dissolving said membrane.

4. The method of claim 1, wherein said surface stabilizing agent comprises at least one surfactant.

5. The method of claim 1, wherein said membrane comprises a polymer.

6. The method of claim 1, further comprising the step of doping said SWNT film.

7. The method of claim 6, wherein said doping comprises adding at least one dopant to said SWNT film, said dopant selected from the group consisting of halogens and alkali metals.

8. The method of claim 1, wherein said SWNT film provides at least 10% optical transmission thoughout the wavelength range from 0.4 μ

m to 10 μ

m.

9. The method of claim 8, wherein a thickness of said SWNT film is at least 100 nm.

10. The method of claim 1, wherein said SWNT film provides at least 50% optical transmission throughout the wavelength range from 3 μ

m to 5 μ

m.

11. The method of claim 10, wherein a thickness of said SWNT film is at least 100 nm.

12. The method of claim 1, wherein said SWNT film provides a sheet resistance of less than 200 ohm/sq at a thickness of 100 nm.

13. An optically transparent and electrically conductive single walled carbon nanotubes (SWNT) film, comprising:

a plurality of interpenetrated single walled carbon nanotubes, wherein said film provides a sheet resistance of less than 200 ohm/sq and at least 30% optical transmission at a wavelength of 3 μ

m.

14. The SWNT film of claim 13, wherein said 30% transmission is provided at a wavelength of 5 μ

m.

15. The SWNT film of claim 13, wherein said 30% transmission is provided at a wavelength of 10 μ

m.

16. The SWNT film of claim 13, wherein said film includes at least one dopant.

17. The SWNT film of claim 14, wherein said dopant is selected from the group consisting of halogens and alkali metals.

18. The SWNT film of claim 13, wherein said SWNT film provides at least 10% optical transmission throughout the wavelength range from about 0.4 μ

m to 10 μ

m at a thickness of at least 100 nm.

19. The SWNT film of claim 13, wherein said SWNT film provides at least 50% optical transmission throughout the wavelength range from about 3 μ

m to 5 μ

m at a thickness of at least 100 nm.

20. The SWNT film of claim 13, wherein said SWNT film provides said sheet resistance of less than 200 ohm/sq at a thickness of 100 nm.