Electro-optical element including IMI coatings

• US 7,830,583 B2
• Filed: 03/05/2007
• Issued: 11/09/2010
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Vander Zwaag, Scott W., Neuman, George A., Anderson, John S., Luten, Henry A., Forgette, Jeffrey A.
• Primary Examiner(s): Lester; Evelyn A.
• Application Number:
  US11/682,121
• Publication Number:
  US 20070206263A1
• Time in Patent Office: 1,345 Days
• Field of Search: 359265-275
• US Class Current: 359/265
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136204 Arrangements to prevent high voltage or static electricity failures
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 1/161 Gaskets; Spacers; Sealing of cells; Filling or closing of cells
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2201/48 Flattening arrangements

Abstract

An electrochromic element comprises a first substrate having a first surface and a second surface opposite the first surface, a second substrate in spaced-apart relationship to the first substrate and having a third surface facing the second surface and a fourth surface opposite the third surface, and an electrochromic medium located between the first and second substrates, wherein the electrochromic medium has a light transmittance that is variable upon application of an electric field thereto. The electrochromic element further comprises a transparent electrode layer covering at least a portion of at least a select one of the first surface, the second surface, the third surface, and the fourth surface, wherein the transparent electrode layer comprises an insulator/metal/insulator stack. The materials utilized to construct the insulator/metal/insulator stack are selected to optimize optical and physical properties of the electrochromic element such as reflectivity, color, electrical switch stability, and environmental durability.

Claims

1. An electrochromic element comprising:

a first substrate having a first surface and a second surface opposite the first surface;

a second substrate having third and fourth surfaces, the first and second substrates disposed in a parallel and spaced apart relationship so as to define a gap therebetween, the second and third surfaces opposing each other;

an electrochromic medium located in the gap, the electrochromic medium having a light transmittance that is variable upon the application of an electric field thereto; and

a transparent electrode layer covering at least a portion of at least a select one of the second surface and the third surface,

wherein the transparent electrode layer comprises a stack including a first insulator layer, at least one metal layer and a second insulator layer, and

wherein the transparent electrode layer is characterized by a color rendering index of greater than or equal to 80.

2. The electrochromic element of claim 1, wherein the transparent electrode layer is characterized by a color rendering index of greater than or equal to 90.

3. The electrochromic element of claim 2, wherein the transparent electrode layer is characterized by a color rendering index of greater than or equal to 95.

4. The electrochromic element of claim 1, wherein the at least one metal layer is a single metal layer comprises silver, and wherein the single metal layer has a thickness of between 50 angstroms and 500 angstroms.

5. The electrochromic element of claim 4, wherein the single metal layer has a thickness of between 75 angstroms and 250 angstroms.

6. The electrochromic element of claim 5, wherein the single metal layer has a thickness of between 100 angstroms and 150 angstroms.

7. The electrochromic element of claim 1, wherein a total thickness of the stack including the first insulator layer, the at least one metal layer and the second insulator layer is between 100 angstroms and 700 angstroms.

8. The electrochromic element of claim 1, wherein a solar heat gain coefficient of the electrochromic element in the clear state is less than or equal to 0.70.

9. The electrochromic element of claim 8, wherein the solar heat gain coefficient of the electrochromic element is less than or equal to 0.50.

10. The electrochromic element of claim 9, wherein the solar heat gain coefficient of the electrochromic element is less than or equal to 0.30.

11. An electrochromic element comprising:

a first substrate having a first surface and a second surface opposite the first surface;

a second substrate having third and fourth surfaces, the first and second substrates disposed in a parallel and spaced apart relationship so as to define a gap therebetween, the second and third surfaces opposing each other;

an electrochromic medium located in the gap, the electrochromic medium having a light transmittance that is variable upon the application of an electric field thereto; and

a transparent electrode layer covering at least a portion of at least a select one of the second surface and the third surface, wherein the transparent electrode layer comprises a stack including a first insulator layer, at least one metal layer and a second insulator layer,

wherein at least one of the first insulator layer and the second insulator layer comprises at least a select one of indium zinc oxide, indium tin oxide, aluminum zinc oxide, titanium oxide, zinc oxide, electrically conductive TiO2, CeOx, tin dioxide, silicon nitride, silicon dioxide, ZnS, chromium oxide, niobium oxide, ZrOx, WO₃, nickel oxide, IrO₂ and

wherein the insulating layer of the stack that is in contact with the electrochromic medium has a resistance of greater than or equal to 10 MOhms.

12. An electrochromic element comprising:

a first substrate having a first surface and a second surface opposite the first surface;

a second substrate having third and fourth surfaces, the first and second substrates disposed in a parallel and spaced apart relationship so as to define a gap therebetween, the second and third surfaces opposing each other;

an electrochromic medium located in the gap, the electrochromic medium having a light transmittance that is variable upon the application of an electric field thereto;

a transparent electrode layer covering at least a portion of at least a select one of the second surface and the third surface, wherein the transparent electrode layer comprises a stack including a first insulator layer, at least one metal layer and a second insulator layer; and

a barrier layer positioned between the first insulator layer of the stack and the select surface that the transparent electrode layer covers,

wherein at least one of the first insulator layer and the second insulator layer comprises at least a select one of indium zinc oxide, indium tin oxide, aluminum zinc oxide, titanium oxide, zinc oxide, electrically conductive TiO2, CeOx, tin dioxide, silicon nitride, silicon dioxide, ZnS, chromium oxide, niobium oxide, ZrOx, WO₃, nickel oxide, IrO₂, and

wherein the barrier layer comprises at least a select one of ruthenium, NiCr, NiCrOx, copper, titanium, niobium, nickel, palladium, platinum, and combinations thereof

13. The electrochromic element of claim 12, wherein the barrier layer has a thickness of less than or equal to 40 angstroms.

14. The electrochromic element of claim 13, wherein the thickness of the barrier layer is less than or equal to 20 angstroms.

15. An electrochromic element comprising:

a first substrate having a first surface and a second surface opposite the first surface;

a second substrate having third and fourth surfaces, the first and second substrates disposed in a parallel and spaced apart relationship so as to define a gap therebetween, the second and third surfaces opposing each other;

an electrochromic medium located in the gap, the electrochromic medium having a light transmittance that is variable upon the application of an electric field thereto;

a transparent electrode layer covering at least a portion of at least a select one of the second surface and the third surface, wherein the transparent electrode layer comprises a stack including a first insulator layer, at least one metal layer and a second insulator layer; and

a barrier layer positioned between the first insulator layer of the stack and the select surface that the transparent electrode layer covers,

wherein at least one of the first insulator layer and the second insulator layer comprises at least a select one of indium zinc oxide, indium tin oxide, aluminum zinc oxide, titanium oxide, zinc oxide, electrically conductive TiO2, CeOx, tin dioxide, silicon nitride, silicon dioxide, ZnS, chromium oxide, niobium oxide, ZrOx, WO₃ nickel oxide, IrO₂, and

wherein the barrier layer comprises at least a select one of silica, doped silica, phosphorus-doped silica, amorphous alumina, aluminum phosphate, SiN, and SnZnOx.

16. The electrochromic element of claim 15, wherein the barrier layer has a thickness of less than or equal to 150 angstroms.

17. The electrochromic element of claim 16, wherein the thickness of the barrier layer is less than or equal to 100 angstroms.

18. The electrochromic element of claim 17, wherein the thickness of the barrier layer is less than or equal to 50 angstroms.

19. An electrochromic element comprising:

a first substrate having a first surface and a second surface opposite the first surface;

a second substrate having third and fourth surfaces, the first and second substrates disposed in a parallel and spaced apart relationship so as to define a gap therebetween, the second and third surfaces opposing each other;

an electrochromic medium located in the gap, the electrochromic medium having a light transmittance that is variable upon the application of an electric field thereto; and

a transparent electrode layer covering at least a portion of at least a select one of the second surface and the third surface,

wherein the transparent electrode layer comprises a stack including a first insulator layer proximate the electrochromic medium, at least one metal layer and a second insulator layer, and

wherein the first insulator comprises indium tin oxide, and wherein the transmittance of the transparent electrode is greater than or equal to about 75%.

20. The electrochromic element of claim 19, wherein in the first insulating layer that is in contact with the electrochromic medium has a resistance of greater than or equal to 10 MOhms.

21. The electrochromic element of claim 19, further comprising:

a barrier layer positioned between the first insulator layer of the stack and the select surface that the transparent electrode layer covers, wherein the barrier layer comprises at least a select one of ruthenium, NiCr, NiCrOx, copper, titanium, niobium, nickel, palladium, platinum, and combinations thereof.

22. The electrochromic element of claim 21, wherein the barrier layer has a thickness of less than or equal to 40 angstroms.

23. The electrochromic element of claim 22, wherein the thickness of the barrier layer is less than or equal to 20 angstroms.

24. The electrochromic element of claim 19, further comprising:

a barrier layer positioned between the first insulator layer of the stack and the select surface that the transparent electrode layer covers, wherein the barrier layer comprises at least a select one of silica, doped silica, phosphorus-doped silica, amorphous alumina, aluminum phosphate, SiN SnZnOx or other chemically inert, non-absorbing dielectric layers and combinations thereof.

25. The electrochromic element of claim 24, wherein the barrier layer has a thickness of less than or equal to 150 angstroms.

26. The electrochromic element of claim 25, wherein the thickness of the barrier layer is less than or equal to 100 angstroms.

27. The electrochromic element of claim 26, wherein the thickness of the barrier layer is less than or equal to 50 angstroms.

28. An electrochromic element comprising:

a first substrate having a first surface and a second surface opposite the first surface;

a second substrate having third and fourth surfaces, the first and second substrates disposed in a parallel and spaced apart relationship so as to define a gap therebetween, the second and third surfaces opposing each other;

an electrochromic medium located in the gap, the electrochromic medium having a light transmittance that is variable upon the application of an electric field thereto; and

a transparent electrode layer covering at least a portion of at least a select one of the second surface and the third surface, wherein the transparent electrode layer comprises a stack including a first insulator layer, a metal layer, and a second insulator layer, and an electrical stabilization layer positioned between the metal layer and at least one of the insulator layers,

wherein the electrical stabilization layer increases a value of a breakdown potential of the metal layer by at least about 0.05 volts.

29. The electrochromic element of claim 28, wherein the metal layer comprises silver.

30. The electrochromic element of claim 28, wherein the electrical stabilization layer comprises at least one of gold, ruthenium, rhodium, palladium, cadmium, copper, nickel, platinum, and indium.

31. The electrochromic element of claim 28, wherein the electrical stabilization layer increases the value of a breakdown potential of the metal layer by about 0.10 volts.

32. The electrochromic element of claim 28, wherein the electrical stabilization layer increases the value of a breakdown potential of the metal layer by about 0.20 volts.

33. The electrochromic element of claim 28, wherein the electrical stabilization layer increases the value of a breakdown potential of the metal layer by about 0.30 volts.

34. The electrochromic element of claim 28, wherein the metal layer is alloyed with a noble metal that is different than a base metal of which the metal layer is comprised.

35. The electrochromic element of claim 28, wherein the metal layer is doped with at least a select one of indium and titanium.

36. The electrochromic element of claim 35, further including:

a barrier layer located between the select surface and the first insulator layer of the stack, wherein the barrier layer comprises at least a select one of silica, doped silica, phosphorus-doped silica, amorphous alumina, aluminum phosphate, SiN SnZnOx or other chemically inert, non-absorbing dielectric layers and combinations thereof.

37. The electrochromic element of claim 36, wherein the barrier layer is amorphous.

38. The electrochromic element of claim 28, wherein the metal layer is doped with at least a select one of palladium, copper, indium, titanium, and combinations thereof.

39. An electrochromic element comprising:

a first substrate having a first surface and a second surface opposite the first surface;

a second substrate having third and fourth surfaces, the first and second substrates disposed in a parallel and spaced apart relationship so as to define a gap therebetween, the second and third surfaces opposing each other;

an electrochromic medium located in the gap, the electrochromic medium having a light transmittance that is variable upon the application of an electric field thereto; and

a transparent electrode layer covering at least a portion of at least a select one of the second surface and the third surface, wherein the transparent electrode layer comprises a stack including a first insulator layer, a metal layer, and a second insulator layer,

wherein the metal layer comprises silver and at least one of the first insulator layer and the second insulator layer comprises at least one of zinc oxide and Sb, and

wherein any of the first and second insulator layers has an absolute stress of less than 3 GPa.

40. The electrochromic element of claim 39, wherein the absolute stress of any of the first and second insulator layers is less than 1.5 GPa.

41. The electrochromic element of claim 40, wherein the absolute stress of any of the first and second insulator layers is less than 0.5 GPa.