Electronic devices including transparent conductive coatings including carbon nanotubes and nanowire composites, and methods of making the same

• US 20110214728A1
• Filed: 03/04/2010
• Published: 09/08/2011
• Est. Priority Date: 03/04/2010
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Veerasamy, Vijayen S.
• Granted Patent: US 8,604,332 B2
• Time in Patent Office: Days
• US Class Current: 136/256
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: F25D 21/04 Preventing the formation of frost or condensate
• CPC Class Codes: F25D 29/00 Arrangement or mounting of control or safety devices
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H01B 1/04 mainly consisting of carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01L 31/035227 the quantum structure being quantum wires, or nanorods carbon nanotubes H10K85/211
• CPC Class Codes: H05K 1/09 Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 2201/026 Nanotubes or nanowires
• CPC Class Codes: H05K 2201/0323 Carbon
• CPC Class Codes: H10K 30/821 comprising carbon nanotubes
• CPC Class Codes: H10K 71/30 Doping active layers, e.g. electron transporting layers
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: H10K 85/225 comprising substituents
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Certain example embodiments of this invention relate to large-area transparent conductive coatings (TCCs) including carbon nanotubes (CNTs) and nanowire composites, and methods of making the same. The σ_dc/σ_opt ratio of such thin films may be improved via stable chemical doping and/or alloying of CNT-based films. The doping and/or alloying may be implemented in a large area coating system, e.g., on glass and/or other substrates. In certain example embodiments, a CNT film may be deposited and then doped via chemical functionalization and/or alloyed with silver and/or palladium. Both p-type and n-type dopants may be used in different embodiments of this invention. In certain example embodiments, silver and/or other nanowires may be provided, e.g., to further decrease sheet resistance. Certain example embodiments may provide coatings that approach, meet, or exceed 90% visible transmission and 90 ohms/square target metrics.

Claims

1. A solar cell, comprising:

a glass substrate;

a first CNT-based conductive layer located, directly or indirectly, on the glass substrate;

a first semiconductor layer in contact with the first CNT-based conductive layer;

at least one absorbing layer located, directly or indirectly, on the first semiconductor layer;

a second semiconductor layer located, directly or indirectly, on the at least one absorbing layer;

a second CNT-based conductive layer in contact with the second semiconductor layer; and

a back contact located, directly or indirectly, on the second CNT-based conductive layer.

2. The solar cell of claim 1, further comprising an antireflective coating provided on a surface of the substrate opposite the first CNT-based conductive layer.

3. The solar cell of claim 1, wherein the first semiconductor layer is an n-type semiconductor layer and the first CNT-based layer is doped with n-type dopants.

4. The solar cell of claim 3, wherein the second semiconductor layer is a p-type semiconductor layer and the second CNT-based layer is doped with p-type dopants.

5. The solar cell of claim 4, further comprising a layer of zinc-doped tin oxide interposed between the glass substrate and the first CNT-based layer.

6. The solar cell of claim 1, wherein the first and/or second semiconductor layers comprise polymeric material(s).

7. A photovoltaic device, comprising:

a substrate;

at least one photovoltaic thin-film layer;

first and second electrodes; and

first and second transparent, conductive CNT-based layers;

wherein the first and second CNT-based layers are respectively doped with n- and p-type dopants.

8. A touch panel subassembly, comprising:

a glass substrate;

a first transparent, conductive CNT-based layer provided, directly or indirectly, on the glass substrate;

a deformable foil, the deformable foil being substantially parallel and in spaced apart relation to the glass substrate; and

a second transparent, conductive CNT-based layer provided, directly or indirectly, on the deformable foil.

9. The touch panel subassembly of claim 8, wherein the first and/or second CNT-based layer(s) is patterned.

10. The touch panel subassembly of claim 9, further comprising:

a plurality of pillars located between the deformable foil and the glass substrate, and

at least one edge seal at the periphery of the subassembly.

11. The touch panel subassembly of claim 10, wherein the deformable foil is a PET foil.

12. The touch panel subassembly of claim 8, wherein the first and/or second CNT-based layer(s) has/have a sheet resistance of less than 500 ohms/square.

13. The touch panel subassembly of claim 8, wherein the first and/or second CNT-based layer(s) has/have a sheet resistance of less than 300 ohms/square.

14. A touch panel apparatus, comprising:

the touch panel subassembly of claim 8; and

a display connected to a surface of the substrate of the touch panel subassembly opposite the deformable foil.

15. The touch panel apparatus of claim 14, wherein the display is an LCD display.

16. The touch panel apparatus of claim 15, wherein the touch panel apparatus is a capacitive touch panel apparatus.

17. The touch panel apparatus of claim 15, wherein the touch panel apparatus is a resistive touch panel apparatus.

18. A data/bus line, comprising a CNT-based layer supported by a substrate, wherein:

a portion of the CNT-based layer has been exposed to an ion beam/plasma treatment and/or etched with H*, thereby reducing conductivity of the portion.

19. The data/bus line of claim 18, wherein the portion is not electrically conductive.

20. The data/bus line of claim 18, wherein the substrate is a glass substrate.

21. The data/bus line of claim 18, wherein the substrate is a silicon wafer.

22. The data/bus line of claim 18, wherein the portion is at least partially removed by exposure to the ion beam/plasma treatment and/or the etching with H*.

23. A method of making an electronic device, the method comprising:

providing a substrate;

forming a CNT-based layer on the substrate;

doping the CNT-based layer; and

selectively patterning the CNT-based layer by one of;

ion beam/plasma exposure and etching with H*.

24. The method of claim 23, further comprising alloying or metalizing at least a portion of the CNT-based layer using a palladium-inclusive solution and/or a silver-inclusive solution.

25. The method of claim 24, wherein the patterning is performed to reduce conductivity and/or remove portions of the CNT-based layer.

26. The method of claim 25, further comprising providing a protective mask over portions of the CNT-based layer prior to the patterning.

27. The method of claim 26, wherein the protective mask comprises a photoresist material.

28. The method of claim 27, further comprising removing the protective mask.

29. A method of making an article for a refrigeration or freezer unit, the method comprising:

providing first and second substantially parallel and spaced apart glass substrates, the first substrate being provided for an interior side of the article and the second substrate being provided for an exterior side of the article;

disposing one or more transparent conductive coatings (TCCs), respectively, on one or more major surfaces of the first and/or second substrates; and

thermally tempering at least the first and second substrates,

wherein each said TCC includes at least one CNT-inclusive layer.

30. The method of claim 29, further comprising connecting the at least one CNT-inclusive layer to a power source such that, in operation, the at least one CNT-inclusive layer receives current from the power source to selectively defog and/or deice the article.

31. A rain sensor comprising:

a sensing circuit comprising at least first and second sensing capacitors that are sensitive to moisture on an external surface of a window, each said sensing capacitor including at least one CNT-based layer;

the sensing circuit further comprising at least one mimicking capacitor that mimics at least one of charging and discharging of at least one of the first and second sensing capacitors;

wherein a writing pulse causes at least the first sensing capacitor to be charged, and an erasing pulse causes each of the first sensing capacitor and the mimicking capacitor to substantially discharge;

wherein presence of rain on the external surface of the window in a sensing field of the first sensing capacitor causes a voltage at an output electrode of the mimicking capacitor to fluctuate in a manner proportional to fluctuation of voltage at an output electrode of the first sensing capacitor, even though the rain is not present in a field of the mimicking capacitor;

wherein rain is detected based on an output signal from the output electrode of the mimicking capacitor, wherein the output signal is read at least between an end of the writing pulse and a beginning of the erase pulse; and

wherein the mimicking capacitor is physically separated from the sensing capacitors, and wherein the writing pulse causes the first sensing capacitor, but not the second sensing capacitor, to charge and also causes the mimicking capacitor to charge.