Counter electrode for electrochromic devices
The embodiments herein relate to electrochromic stacks, electrochromic devices, and methods and apparatus for making such stacks and devices. In various embodiments, an anodically coloring layer in an electrochromic stack or device is fabricated to include a heterogeneous structure, for example a heterogeneous composition and/or morphology. Such heterogeneous anodically coloring layers can be used to better tune the properties of a device.
1. An electrochromic device comprising:
a substrate;
an electrochromic layer disposed on or over the substrate, said electrochromic layer comprising a cathodically tinting electrochromic material; and
a counter electrode layer also disposed on or over the substrate, said counter electrode layer comprising:
(a) a first sublayer comprising a first anodically tinting material, and
(b) a second sublayer comprising a second anodically tinting material, and
(c) a third sublayer comprising a third anodically tinting electrochromic material,
wherein the first anodically tinting material, second anodically tinting material, and third anodically tinting material have different compositions but each comprise an oxide of at least one transition metal,
wherein the first sublayer is disposed between the electrochromic layer and the second sublayer, and
wherein the second sublayer is disposed between the first sublayer and the third sublayer.
2. The electrochromic device of claim 1 , wherein each of the first and second anodically tinting materials comprises the at least one transition metal and another non-alkali metal.
3. The electrochromic device of claim 2 , wherein the first and second anodically tinting materials each comprise nickel and tungsten.
4. The electrochromic device of claim 3 , wherein the second anodically tinting material further comprises tantalum.
5. The electrochromic device of claim 3 , wherein the second anodically tinting material further comprises niobium.
6. The electrochromic device of claim 3 , wherein the second anodically tinting material further comprises tin.
7. The electrochromic device of claim 2 , wherein the second anodically tinting material comprises the at least one transition metal, the other non-alkali metal, and a second non-alkali metal, and wherein the first anodically tinting material contains the at least one transition metal and the other non-alkali metal as its only metals.
8. The electrochromic device of claim 2 , wherein the first and second anodically tinting materials each comprise the at least one transition metal, the other non-alkali metal, and a second non-alkali metal, and wherein the second anodically tinting material has a higher atomic concentration of the second non-alkali metal in comparison to the first anodically tinting material.
9. The electrochromic device of claim 2 , wherein one of the at least one transition metal is selected from the group consisting of tungsten (W), tantalum (Ta), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), rhodium (Rh), ruthenium (Ru), vanadium (V), iridium (Ir), and combinations thereof.
10. The electrochromic device of claim 9 , wherein the other non-alkali metal is selected from the group consisting of silver (Ag), aluminum (Al), arsenic (As), gold (Ag), boron (B), barium (Ba), beryllium (Be), bismuth (Bi), calcium (Ca), cadmium (Cd), cerium (Ce), cobalt (Co), chromium (Cr), copper (Cu), europium (Eu), iron (Fe), gallium (Ga), gadolinium (Gd), germanium (Ge), hafnium (Hf), mercury (Hg), indium (In), iridium (Ir), lanthanum (La), magnesium (Mg), manganese (Mn), molybdenum (Mo), niobium (Nb), neodymium (Nd), osmium (Os), protactinium (Pa), lead (Pb), palladium (Pd), praseodymium (Pr), promethium (Pm), polonium (Po), platinum (Pt), radium (Ra), rhenium (Re), rhodium (Rh), ruthenium (Ru), antimony (Sb), scandium (Sc), selenium (Se), silicon (Si), samarium (Sm), tin (Sn), strontium (Sr), tantalum (Ta), terbium (Tb), technetium (Tc), tellurium (Te), thorium (Th), titanium (Ti), thallium (Tl), uranium (U), vanadium (V), tungsten (W), yttrium (Y), zinc (Zn), zirconium (Zr), and combinations thereof.
11. The electrochromic device of claim 10 , wherein the other non-alkali metal is selected from the group consisting of silver (Ag), arsenic (As), gold (Au), boron (B), cadmium (Cd), copper (Cu), europium (Eu), gallium (Ga), gadolinium (Gd), germanium (Ge), mercury (Hg), osmium (Os), lead (Pb), palladium (Pd), promethium (Pm), polonium (Po), platinum (Pt), radium (Ra), terbium (Tb), technetium (Tc), thorium (Th), thallium (Tl), and combinations thereof.
12. The electrochromic device of claim 10 , wherein the other non-alkali metal is selected from the group consisting of tantalum (Ta), tin (Sn), and niobium (Nb).
13. The electrochromic device of claim 12 , wherein the other non-alkali metal is tantalum (Ta).
14. The electrochromic device of claim 12 , wherein the other non-alkali metal is tin (Sn).
15. The electrochromic device of claim 12 , wherein the other non-alkali metal is niobium (Nb).
16. The electrochromic device of claim 1 , wherein the first and second anodically tinting materials each comprise a first transition metal, a second transition metal, and oxygen, and wherein a ratio of the first transition metal to the second transition metal is different in the first and second anodically tinting materials.
17. The electrochromic device of claim 1 , wherein the first anodically tinting material comprises the at least one transition metal, a second transition metal, but no other transition metals, and oxygen; the second anodically tinting material comprises the at least one transition metal, the second transition metal, a third transition metal, and oxygen; and the third anodically tinting material comprises the at least one transition metal, the second transition metal, the third transition metal, and oxygen, and wherein the second anodically tinting material and the third anodically tinting material have different concentrations of the third transition metal.
18. The electrochromic device of claim 1 , wherein the first and second sublayers of the counter electrode layer are in physical contact with one another.
19. The electrochromic device of claim 1 , wherein the first and second sublayers of the counter electrode layer are separated from one another by a defect-mitigating-insulating layer, the defect-mitigating-insulating layer having an electronic resistivity of between about 1 and 5×10 10 Ohm-cm.
20. The electrochromic device of claim 1 , wherein the first anodically tinting material has a first affinity for lithium and the second anodically tinting material has a second affinity for lithium, wherein the first affinity for lithium and the second affinity for lithium are different.
21. The electrochromic device of claim 1 , wherein a transmitted b* value of the electrochromic device is about 14 or lower when the electrochromic device is in its clearest state.
22. The electrochromic device of claim 1 , wherein a transmitted b* value of the electrochromic device is about 10 or lower when the electrochromic device is in its clearest state.
23. The electrochromic device of claim 1 , wherein visible transmittance of the electrochromic device is at least about 55% when the electrochromic device is in its clearest state.
24. The electrochromic device of claim 1 , wherein the counter electrode layer has an overall thickness between about 50 nm and about 650 nm.
25. The electrochromic device of claim 1 , wherein the counter electrode layer has an overall thickness between about 100 nm and about 400 nm.
26. The electrochromic device of claim 1 , wherein the counter electrode layer has an overall thickness between about 150 nm and about 300 nm.
27. The electrochromic device of claim 1 , wherein the first and second sublayers of the counter electrode layer each have a morphology that is a mixture of amorphous and nanocrystalline phases with nanocrystallites having a diameter of less than about 50 nm.
28. The electrochromic device of claim 1 , wherein the second sublayer is a defect-mitigating insulating layer having an electronic resistivity between about 1 and 5×10 10 Ohm-cm.
29. The electrochromic device of claim 1 , further comprising a transparent conductive layer disposed on or over the electrochromic layer and the counter electrode layer.
30. The electrochromic device of claim 29 , wherein the transparent conductive layer comprises a doped indium oxide.
31. The electrochromic device of claim 1 , wherein at least one of the first and second anodically tinting materials comprises nickel, aluminum, and oxygen.
32. The electrochromic device of claim 31 , wherein the first anodically tinting material comprises nickel, tungsten, and oxygen, and wherein the second anodically tinting material comprises nickel, aluminum, and oxygen.
33. The electrochromic device of claim 1 , wherein at least one of the first and second anodically tinting materials comprises nickel, silicon, and oxygen.
34. The electrochromic device of claim 33 , wherein the first anodically tinting material comprises nickel, tungsten, and oxygen, and wherein the second anodically tinting material comprises nickel, silicon, and oxygen.