Electro-Optical Element Including IMI Coatings

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is an enlarged cross-sectional view of a prior art electrochromic mirror assembly incorporating a fourth surface reflector;

FIG. 2 is a front elevational view schematically illustrating an inside/outside electrochromatic rearview mirror system for motor vehicles;

FIG. 3 is an enlarged cross-sectional view of an electrochromic mirror incorporating a third surface reflector/electrode taken along the line III-III, FIG. 2;

FIG. 4 is a further enlarged cross-sectional view of a transparent electrode of the area IV, FIG. 3;

FIG. 5 is a graph of reflectance/transmittance versus wavelength of ITO on glass within an incident medium of air or electrochromic fluid;

FIG. 6A-6C are graphs of difference in transmittance between and IMI with air and EC fluid as the incident media for different combinations of layer thickness in a 3-layer IMI stack;

FIG. 7 is a graph of change to transmittance versus soak time of a five layer IMI stack;

FIG. 8 is a graph of a change to resistance versus soak time of a five layer IMI stack;

FIG. 9 is a graph of sheet resistance and transmittance versus oxygen percentage of a two-layer IMI stack;

FIG. 10 is a graph of oxygen percentage versus extinction coefficient versus percent roughness of the two-layer IMI stack; and

FIG. 11 is a graph of wavelength versus reflectance for DOE2 sample 7, 8, and 13.

Claims

1. An electrochromic element comprising: 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;an electrochromic medium located between the first and second substrates, wherein the electrochromic medium has a light transmittance that is variable upon the application of an electric field thereto; anda 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 first insulator layer, at least one metal layer and a second insulator layer, and wherein the electrochromic element displays a color rendering index of greater than or equal to 80.

2. The electrochromic element of claim 1, wherein the electrochromic element displays a color rendering index of greater than or equal to 90.

3. The electrochromic element of claim 2, wherein the electrochromic element displays 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 includes a single metal layer.

5. The electrochromic element of claim 4, wherein the single metal layer comprises silver, and wherein the single metal layer has a thickness of between 50 angstroms and 500 angstroms.

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

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

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

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

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

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

12. An electrochromic element comprising: 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;an electrochromic medium located between the first and second substrates, wherein the electrochromic medium has a light transmittance that is variable upon the application of an electric field thereto; anda 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 first insulator layer, at least one metal layer and a second insulator layer, and wherein at least one of the first insulator layer and the second insulator layer comprises at least a select one of indium zinc oxide, aluminum zinc oxide, titanium oxide, electrically conductive TiO2, CeOx, tin dioxide, silicon nitride, silicon dioxide, ZnS, chromium oxide, niobium oxide, ZrOx, WO3, nickel oxide, IrO2, and combinations thereof.

13. The electrochromic element of claim 12, wherein the select one of the insulator layers is positioned between the at least one metal layer and the select surface that the transparent electrode layer covers.

14. The electrochromic element of claim 12, wherein in the top insulating layer in contact with the electrochromic medium has a conductivity of greater than or equal to 10MOhms.

15. The electrochromic element of claim 12, further comprising: a barrier layer positioned between the first insulator layer 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.

16. The electrochromic element of claim 15, wherein the barrier layer has a thickness of less than or equal to 40 angstroms.

17. The electrochromic element of claim 16, wherein the thickness of the barrier layer is less than or equal to 20 angstroms.

18. The electrochromic element of claim 12, further comprising: a barrier layer positioned between the first insulator layer 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 dielectic layers and combinations thereof.

19. The electrochromic element of claim 18, wherein the barrier layer has a thickness of less than or equal to 150 angstroms.

20. The electrochromic element of claim 19, wherein the thickness of the barrier layer is less than or equal to 100 angstroms.

21. The electrochromic element of claim 20, wherein the thickness of the barrier layer is less than or equal to 50 angstroms.

22. An electrochromic element comprising: 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;an electrochromic medium located between the first and second substrates, wherein the electrochromic medium has a light transmittance that is variable upon the application of an electric field thereto; anda 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 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%.

23. The electrochromic element of claim 22, wherein in the top insulating layer in contact with the electrochromic medium has a conductivity of greater than or equal to 10MOhms.

24. The electrochromic element of claim 22, further comprising: a barrier layer positioned between the first insulator layer 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.

25. The electrochromic element of claim 24, wherein the barrier layer has a thickness of less than or equal to 40 angstroms.

26. The electrochromic element of claim 25, wherein the thickness of the barrier layer is less than or equal to 20 angstroms.

27. The electrochromic element of claim 22, further comprising: a barrier layer positioned between the first insulator layer 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 dielectic layers and combinations thereof.

28. The electrochromic element of claim 27, wherein the barrier layer has a thickness of less than or equal to 150 angstroms.

29. The electrochromic element of claim 28, wherein the thickness of the barrier layer is less than or equal to 100 angstroms.

30. The electrochromic element of claim 29, wherein the thickness of the barrier layer is less than or equal to 50 angstroms.

31. An electrochromic element comprising: 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;an electrochromic medium located between the first and second substrates, wherein the electrochromic medium has a light transmittance that is variable upon the application of an electric field thereto; anda 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 first insulator layer, a metal layer, and a second insulator layer, and an optional electrical stabilization layer position between the metal layer and either insulator layer wherein at least one of the optional electrical stabilization layer or layers comprises at least a select one of gold, ruthenium, rhodium, palladium, cadmium, copper, nickel, platinum, iridium, and combinations thereof.

32. The electrochromic element of claim 31, wherein the metal layer comprises silver.

33. The electrochromic element of claim 31, wherein the select electrical stabilization layer will increase the viable applied potential the metal layer by about 0.05 volts.

34. The electrochromic element of claim 33, wherein the select electrical stabilization layer will increase the viable applied potential the metal layer by about 0.10 volts.

35. The electrochromic element of claim 34, wherein the select electrical stabilization layer will increase the viable applied potential the metal layer by about 0.20 volts.

36. The electrochromic element of claim 35, wherein the select electrical stabilization layer will increase the viable applied potential the metal layer by about 0.30 volts.

37. The electrochromic element of claim 31, wherein the metal layer is alloyed with a noble metal that is different than a base metal of which the metal layer is comprised.

38. The electrochromic element of claim 31, wherein the metal layer is doped with at least a select one of indium and titanium.

39. An electrochromic element comprising: 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;an electrochromic medium located between the first and second substrates, wherein the electrochromic medium has a light transmittance that is variable upon the application of an electric field thereto; anda 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 first insulator layer, a metal layer, and a second insulator layer, and wherein the metal layer comprises silver and at least one of the first insulator layer and the second insulator layer comprises zinc oxide or Sb and combinations thereof.

40. The electrochromic element of claim 39, wherein at least a select one of the select insulator layers and a surface of the metal layer covers is at a low energy state.

41. The electrochromic element of claim 39, wherein the at least select one of the select insulator layer or other layer below the metal layer and the surface of the metal layer is ion beam treated.

42. The electrochromic element of claim 39, wherein a surface of the layer below the metal layer covered by the select insulator layer is chemically treated.

43. The electrochromic element of claim 42, wherein a surface of the layer below the metal layer is disulfide or SO2 treated.

44. The electrochromic element of claim 31, wherein the metal layer is doped with at least a select one of palladium, copper, indium, titanium, and combinations thereof.

45. The electrochromic element of claim 38, further including: a barrier layer located between the select surface and the first insulator, 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 dielectic layers and combinations thereof.

46. The electrochromic element of claim 45, wherein the barrier layer is amorphous.

47. The electrochromic element of claim 39, wherein the first or second insulator layers have an absolute stress of less than 3 GPa.

48. The electrochromic element of claim 47, wherein the absolute stress of the first or second insulator layer is less than 1.5 GPa.

49. The electrochromic element of claim 48, wherein the absolute stress of the first or second insulator layer is less than 0.5 GPa.

50. A method for manufacturing an electrochromic element, the method comprising: providing a first substrate having a first surface and a second surface opposite the first surface;providing a second substrate having a third surface facing the second surface and a fourth surface opposite the third surface;applying a transparent electrode layer to at least a select one of the second surface and the third surface, wherein the transparent electrode layer comprises a first insulator layer, a metal layer, and a second insulator layer;applying an epoxy to at least a select one of the second surface and the third surface; andsealing the first substrate to the second substrate by applying infrared radiation to the epoxy, wherein the major wavelength of the infrared radiation less than 2.5 microns.

51. The method of claim 50, wherein the step of applying the transparent electrode layer includes providing at least a select one of the first insulator layer and the second insulator layer as comprising ITO, IZO, AZO, ZnO, doped-ZnO, TiOx, electrically conductive TiOx, CeOx, SnO2, SiN, SiO2, ZnS, NiOx, CrOx, NbOx, ZrOx, and combinations thereof.