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 nickel-tungsten-niobium-oxide (NiWNbO). This material is particularly beneficial in that it is very transparent in its clear state.
1. An integrated deposition system for fabricating an electrochromic stack, the integrated deposition system comprising:
a plurality of deposition stations aligned in series and interconnected and operable to pass a substrate from one station to the next without exposing the substrate to an external environment, wherein the plurality of deposition stations comprise
(i) a first deposition station containing a first one or more material sources for depositing a cathodically coloring layer;
(ii) a second deposition station containing a second one or more material sources for depositing an anodically coloring layer comprising nickel-tungsten-niobium-oxide (NiWNbO); and
a controller containing program instructions for passing the substrate through the plurality of deposition stations in a manner that deposits on the substrate (i) the cathodically coloring layer, and (ii) the anodically coloring layer to form a stack comprising at least the cathodically coloring layer and the anodically coloring layer,
wherein the NiWNbO has an atomic ratio of Ni:(W+Nb) that is between about 1.5:1 and 3:1, and
wherein the NiWNbO has an atomic ratio of W:Nb that is between about 0.2:1 and 1:1.
2. The integrated deposition system of claim 1 , wherein the NiWNbO has an atomic ratio of Ni:(W+Nb) that is between about 1.5:1 and 2.5:1.
3. The integrated deposition system of claim 2 , wherein the NiWNbO has an atomic ratio of Ni:(W+Nb) that is between about 1.8:1 and 2.5:1.
4. The integrated deposition system of claim 3 , wherein the NiWNbO has an atomic ratio of Ni:(W+Nb) that is between about 2:1 and 2.5:1.
5. The integrated deposition system of claim 1 , wherein the NiWNbO has an atomic ratio of Ni:(W+Nb) that is between about 2:1 and 3:1.
6. The integrated deposition system of claim 1 , wherein the NiWNbO has an atomic ratio of W:Nb that is between about 0.2:1 and 1:1.
7. The integrated deposition system of claim 6 , wherein the NiWNbO has an atomic ratio of W:Nb that is between about 1:1 and 2:1.
8. The integrated deposition system of claim 1 , wherein at least one of the second one or more material sources for depositing the anodically coloring layer comprise an elemental metal selected from the group consisting of: nickel, tungsten, and niobium.
9. The integrated deposition system of claim 1 , wherein at least one of the second one or more material sources for depositing the anodically coloring layer comprise an alloy comprising two or more metals selected from the group consisting of: nickel, tungsten, and niobium.
10. The integrated deposition system of claim 1 , wherein at least one of the second one or more material sources for depositing the anodically coloring layer comprise an oxide.
11. The integrated deposition system of claim 1 , wherein the integrated deposition system is configured to deposit the anodically coloring layer as a substantially amorphous material.
12. The integrated deposition system of claim 1 , wherein the integrated deposition system is configured to deposit the cathodically coloring layer and the anodically coloring layer in direct physical contact with one another.
13. The integrated deposition system of claim 1 , wherein the controller contains program instructions for depositing the anodically coloring layer as two or more sub-layers having different compositions and/or morphologies.
14. The integrated deposition system of claim 1 , wherein the cathodically coloring layer comprises tungsten oxide (WOx).