Transparent electrical conductors prepared from sorted carbon nanotubes and methods of preparing same

• US 8,323,784 B2
• Filed: 08/25/2008
• Issued: 12/04/2012
• Est. Priority Date: 08/29/2007
• Status: Active Grant

• Current Assignee: Northwestern University
• Original Assignee: Northwestern University
• Inventors: Green, Alexander A., Hersam, Mark C.
• Primary Examiner(s): Ewald, Maria Veronica
• Assistant Examiner(s): FERGUSON, LAWRENCE D
• Application Number:
  US12/229,595
• Publication Number:
  US 20090061194A1
• Time in Patent Office: 1,562 Days
• Field of Search: 428/220, 428/336, 428/439
• US Class Current: 428/220
• 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 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08K 3/041 Carbon nanotubes
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: C09D 7/61 inorganic
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

Various methods related to the preparation of transparent electrical conductors based on carbon nanotubes having enhanced optical and electrical properties are disclosed. In some embodiments, the methods involve employing carbon nanotubes that have been presorted according to electronic type and/or optical absorbance for use in transparent electrical conductors. Other embodiments involve use of carbon nanotube bundles that have been pre-sorted according to bundle density.

Claims

1. A colored transparent conductive film comprising:

an average transmittance of greater than about 75% in the visible spectrum;

a sheet resistance of less than about 1.0×

10³ Ω

/square; and

a visible color, the visible color essentially one color selected from colors of the visible spectrum, said selected visible color transmitted;

wherein the film comprises single-walled carbon nanotubes having a mean diameter with a diameter variance for differential wavelength absorption in the visible spectrum to provide the visible color of the film.

2. The colored transparent conductive film of claim 1, wherein the film consists essentially of metallic single-walled carbon nanotubes.

3. The colored transparent conductive film of claim 1, wherein the single-walled carbon nanotubes have a diameter variance of less than or about ±

0.1 nm.

4. The colored transparent conductive film of claim 1, wherein the single-walled carbon nanotubes have a mean diameter selected from about 0.9 nm, about 1.0 nm, about 1.1 nm, about 1.3 nm, about 1.4 nm, and about 1.6 nm.

5. The colored transparent conductive film of claim 1, wherein the visible color is selected from cyan, magenta, yellow, violet, and green.

6. The colored transparent conductive film of claim 1, wherein the single-walled carbon nanotubes are produced by laser ablation, arc discharge, or high-pressure carbon monoxide conversion.

7. The colored transparent conductive film of claim 1, wherein the film has a sheet resistance of less than about 600 Ω

/square.

8. The colored transparent conductive film of claim 1, wherein the film has a transmittance of greater than about 80% at 550 nm.

9. The colored transparent conductive film of claim 1, wherein the film has a thickness less than about 100 nm.

10. A colored transparent conductive film comprising single-walled carbon nanotubes, wherein greater than about 50% of the single-walled carbon nanotubes are metallic, the film with an average transmittance of greater than about 75% in the visible spectrum and having a visible color, the visible color essentially one color selected from colors of the visible spectrum, said selected visible color transmitted.

11. The colored transparent conductive film of claim 10, wherein greater than about 80% of the single-walled carbon nanotubes are metallic.

12. The colored transparent conductive film of claim 10, wherein greater than about 95% of the single-walled carbon nanotubes are metallic.

13. The colored transparent conductive film of claim 10, wherein the single-walled carbon nanotubes have a diameter variance of less than or about ±

0.1 nm.

14. The colored transparent conductive film of claim 10, wherein the single-walled carbon nanotubes have a mean diameter selected from about 0.9 nm, about 1.0 nm, about 1.1 nm, about 1.3 nm, about 1.4 nm, and about 1.6 nm.

15. A colored transparent conductive film comprising single-walled carbon nanotubes, wherein greater than about 80% of the single-walled carbon nanotubes are metallic, the film having a visible color and a sheet resistance of less than about 1.0×

10³ Ω

/square, the visible color essentially one color selected from colors of the visible spectrum, said selected visible color transmitted.

16. The colored transparent conductive film of claim 15, wherein greater than about 95% of the single-walled carbon nanotubes are metallic.

17. The colored transparent conductive film of claim 15, wherein the single-walled carbon nanotubes have a diameter variance of less than or about ±

0.1 nm.

18. The colored transparent conductive film of claim 15, wherein the single-walled carbon nanotubes have a mean diameter selected from about 0.9 nm, about 1.0 nm, about 1.1 nm, about 1.3 nm, about 1.4 nm, and about 1.6 nm.

19. The colored transparent conductive film of claim 15, wherein the film has an average transmittance of greater than about 75% in the visible range.

20. The colored transparent conductive film of claim 19, wherein the transparent conductive film has an average transmittance of greater than about 80% at a wavelength of 550 nm, and a sheet resistance of less than about 600 Ω

/square.