Articles with resistance gradients for uniform switching

• US 10,739,660 B2
• Filed: 09/21/2017
• Issued: 08/11/2020
• Est. Priority Date: 09/23/2016
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Owings, Robert R.
• Primary Examiner(s): Thompson, Timothy J
• Assistant Examiner(s): Azam, Muhammed
• Application Number:
  US16/331,323
• Publication Number:
  US 20190353970A1
• Time in Patent Office: 1,055 Days
• Field of Search: None
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 2001/1552 Inner electrode, e.g. the electrochromic layer being sandwiched between the inner electrode and the support substrate
• CPC Class Codes: H01B 5/14 comprising conductive layers or films on insulating-supports

Abstract

An article includes a transparent non-conducting layer, wherein a thickness of the transparent non-conducting layer continuously decreases in a first direction; and a transparent conducting layer on the transparent non-conducting layer, wherein a thickness of the transparent conducting layer continuously decreases in a direction opposite to the first direction. A thickness of the article is substantially uniform. A sheet resistance, R_s, to a flow of electrical current through the transparent conducting layer, varies as a function of position in the transparent conducting layer. A ratio of a value of maximum sheet resistance, R_max, to a value of minimum sheet resistance, R_min, in the transparent conducting layer is at least 1.5.

Claims

1. An article comprising:

a transparent non-conducting layer, wherein a thickness of the transparent non-conducting layer continuously decreases in a first direction; and

a transparent conducting layer on the transparent non-conducting layer, wherein a thickness of the transparent conducting layer continuously decreases in a direction opposite to the first direction;

wherein a thickness of the article is substantially uniform;

wherein a sheet resistance, R_s, to a flow of electrical current through the transparent conducting layer, varies as a function of position in the transparent conducting layer;

wherein a ratio of a value of maximum sheet resistance, R_max, to a value of minimum sheet resistance, R_min, in the transparent conducting layer is at least 1.5; and

wherein the article is transparent to electromagnetic radiation having a wavelength from 300 to 5000 nm.

2. The article of claim 1, wherein the ratio of the value of maximum sheet resistance, R_max, to the value of minimum sheet resistance, R_min, in the transparent conducting layer is at least 5.

4. The article of claim 1, wherein the visible light transmission of the article is more than 40%.

5. The article of claim 1, wherein the visible light transmission of the article varies less than 10% in the first direction or a third direction perpendicular to the first direction.

6. The article of claim 1, wherein the visible light transmission of the article varies less than 5% in the first direction or a third direction perpendicular to the first direction.

7. The article of claim 1, wherein the reflectance of the article varies less than 4% in the first direction or a third direction perpendicular to the first direction.

8. The article of claim 1, further comprising a substrate.

3. An article comprising:

a first transparent conducting layer, wherein a thickness of the first transparent conducting layer continuously decreases in a first direction and the first transparent conducting layer has a first bulk resistivity; and

a second transparent conducting layer on the first transparent conducting layer, wherein a thickness of the second transparent conducting layer continuously decreases in a direction opposite to the first direction and the second transparent conducting layer has a second bulk resistivity;

wherein a thickness of the article is substantially uniform;

wherein the first bulk resistivity is higher than the second bulk resistivity;

wherein a sheet resistance, R_s of the article, varies as a function of position in the transparent conducting layer;

wherein a ratio of a value of maximum sheet resistance, R_max, to a value of minimum sheet resistance, R_min in the article is at least 1.5; and

wherein the first bulk resistivity is from 600 to 800 μ

Ω

·

cm.

12. The article of claim 3, wherein a visible light transmission of the article varies less than 5% in the first direction or a third direction perpendicular to the first direction.

16. The article of claim 3, wherein a visible light transmission of the article varies less than 10% in the first direction or a third direction perpendicular to the first direction.

17. The article of claim 3, wherein the second bulk resistivity is from 50 to 400 μ

Ω

·

cm.

9. A device comprising:

a first transparent substrate;

a first transparent non-conducting layer on the first transparent substrate, wherein a thickness of the first transparent non-conducting layer continuously decreases in a first direction; and

a first transparent conducting layer on the first transparent non-conducting layer, wherein a thickness of the first transparent conducting layer continuously decreases in a direction opposite to the first direction;

wherein a sheet resistance, R_s, to a flow of electrical current through the first transparent conducting layer, varies as a function of position in the first transparent conducting layer;

wherein a ratio of a value of maximum sheet resistance, R_max, to a value of minimum sheet resistance, R_min, in the first transparent conducting layer is at least 1.5; and

wherein the device is transparent to electromagnetic radiation having a wavelength from 300 to 5000 nm.

10. The device of claim 9, further comprising

a second transparent conducting layer, the first transparent conducting layer being located between the first transparent non-conducting layer and the second transparent conducting layer;

and

a second transparent non-conducting layer on second transparent conducting layer;

wherein a thickness of the second transparent non-conducting layer continuously decreases in a second direction and a thickness of the first transparent conducting layer continuously decreases in a fourth direction opposite to the second direction;

wherein a sheet resistance, R_s, to another flow of electrical current through the second transparent conducting layer, varies as a function of position in the second transparent conducting layer; and

wherein a ratio of a value of maximum sheet resistance, R_max, to a value of minimum sheet resistance, R_min, in the second transparent conducting layer is at least 1.5.

11. The device of claim 10, further comprising a second substrate, the second transparent non-conducting layer being between the second substrate and the second transparent conducting layer.

13. The device of claim 9, wherein a visible light transmission of the device is more than 40%.

14. The device of claim 9, wherein a visible light transmission of the device varies less than 10% in the first direction or a third direction perpendicular to the first direction.

15. The device of claim 9, wherein a visible light transmission of the device varies less than 5% in the first direction or a third direction perpendicular to the first direction.