Optical device fabrication

• US 10,126,622 B2
• Filed: 09/27/2012
• Issued: 11/13/2018
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Starkey Laboratories Incorporated, View Incorporated
• Original Assignee: View Incorporated
• Inventors: Bhatnagar, Yashraj, Rozbicki, Robert T., Mulpuri, Rao
• Primary Examiner(s): Talbot, Brian K
• Application Number:
  US14/347,227
• Publication Number:
  US 20140329006A1
• Time in Patent Office: 2,238 Days
• Field of Search: 427109, 427124, 4271263, 427307, 427 58, 427108, 501 60- 72
• CPC Class Codes: B05D 3/065 After-treatment
• CPC Class Codes: B05D 3/12 by mechanical means
• CPC Class Codes: B05D 5/02 to obtain a matt or rough surface
• CPC Class Codes: B05D 5/12 to obtain a coating with specific electrical properties
• CPC Class Codes: C03B 27/00 Tempering or quenching glass products
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 17/3642 the multilayer coating containing a metal layer
• CPC Class Codes: C03C 2217/94 Transparent conductive oxide layers [TCO] being part of a multilayer coating
• CPC Class Codes: C03C 2218/31 Pre-treatment
• CPC Class Codes: C23C 16/0254 Physical treatment to alter the texture of the surface, e.g. scratching or polishing
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates

Abstract

Transparent conductive coatings are polished using particle slurries in combination with mechanical shearing force, such as a polishing pad. Substrates having transparent conductive coatings that are too rough and/or have too much haze, such that the substrate would not produce a suitable optical device, are polished using methods described herein. The substrate may be tempered prior to, or after, polishing. The polished substrates have low haze and sufficient smoothness to make high-quality optical devices.

Claims

1. A method of fabricating an electrochromic window, the method comprising:

a) receiving a glass substrate having a first transparent conducting layer thereon;

b) tempering the glass substrate;

c) after tempering the glass substrate, polishing the surface of the first transparent conducting layer to reduce surface roughness; and

then

d) fabricating an all solid state and inorganic electrochromic device by;

forming, on the first transparent conducting layer an electrochromic layer, a counter electrode layer and a second transparent conducting oxide layer; and

heating the electrochromic device to form an ion conducting and electronically-insulating region between the electrochromic layer and the counter electrode layer.

2. The method of claim 1, wherein c) is performed to also reduce haze.

3. The method of claim 2, wherein haze is reduced to less than 1%.

4. The method of claim 1, wherein the first transparent conducting layer is a tin oxide based material.

5. The method of claim 4, wherein the tin oxide based material comprises fluorinated tin oxide.

6. The method of claim 5, wherein the tin oxide based material is a pyrolytically-applied coating.

7. The method of claim 1, wherein c) is performed mechanically using an abrasive preparation comprising particles having a Mohs hardness scale factor of at least 9.

8. The method of claim 7, wherein the abrasive preparation comprises alumina.

9. The method of claim 7, wherein the abrasive preparation comprises carborundum.

10. The method of claim 8, wherein the abrasive preparation is an alumina slurry having an average particle diameter of 250 nm or greater.

11. The method of claim 10, wherein the average particle diameter is about 1 μ

m.

12. The method of claim 1, wherein b) is performed for between about 10 minutes and about 90 minutes.

13. The method of claim 1, wherein c) is performed until the surface roughness of the transparent conducting layer has an Ra value of between about 1 nm and about 5 nm.

14. The method of claim 1, wherein b) is performed until the surface roughness of the transparent conducting layer has an Ra value of between about 2 nm and about 3 nm.

15. The method of claim 1, wherein c) is performed until sheet resistance of the transparent conducting layer is between 5 Ohms and 30 Ohms per square.

16. The method of claim 1, wherein sheet resistance of the transparent conducting layer is periodically measured during c).

17. The method of claim 16, wherein c) is performed until the sheet resistance of the transparent conducting layer is between about 5 and about 30 Ohms per square.

18. The method of claim 1, wherein the electrochromic device comprises:

a. a tungsten oxide based electrochromic layer;

b. a nickel tungsten oxide counter electrode layer; and

c. a tin-oxide based second transparent conducting layer.

29. The method of claim 1, wherein d) includes heating the electrochromic device via ultraviolet radiation.

30. The method of claim 1, wherein d) includes heating the electrochromic device to a temperature between about 150°

C. and about 450°

C.

31. The method of claim 1, wherein d) includes heating the electrochromic device under an inert atmosphere and then under O₂.

19. A method of fabricating an electrochromic window, the method comprising:

a) providing a glass substrate having a first transparent conducting layer thereon;

b) tempering the glass substrate

c) after tempering the glass substrate, polishing the first transparent conducting layer using an alumina slurry having an average particle size of between about 0.1 μ

m and about 1 μ

m; and

d) fabricating an all solid-state and inorganic electrochromic device by;

depositing on the first transparent conducting layer, having been polished, a tungsten oxide based electrochromic layer, a nickel tungsten oxide based counter electrode layer and a second transparent conducting layer; and

heating the electrochromic device to form an ion conducting and electronically-insulating region between the electrochromic layer and the counter electrode layer,

wherein the electrochromic device is fabricated in an apparatus where the layers of the electrochromic device are deposited without leaving the apparatus and without breaking vacuum.

20. The method of claim 19, wherein c) is performed to reduce surface roughness.

21. The method of claim 19, wherein c) is performed to reduce haze.

22. The method of claim 21, wherein haze is reduced to less than 1%.

23. The method of claim 19, wherein c) is performed to reduce surface roughness and haze.

24. The method of claim 19, wherein the first transparent conducting layer is a tin oxide based material.

25. The method of claim 19, wherein the glass substrate is non-tempered float glass and the first transparent conducting layer comprises tin oxide.

26. The method of claim 19, wherein the alumina slurry has average particle size of between about 0.25 μ

m and about 1 μ

m.

27. The method of claim 19, wherein d) further includes deposition of lithium metal.

28. The method of claim 19, wherein c) is performed until sheet resistance of the first transparent conductive coating is between about 5 and about 30 Ohms per square.