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,
wherein the first and second anodically tinting materials have different compositions but each comprise an oxide of at least one transition metal, and
wherein the first sublayer is disposed between the electrochromic layer and the second 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 a material selected from the group consisting of tantalum, niobium, and tin.
5. 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.
6. 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.
7. 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.
8. The electrochromic device of claim 7 , 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.
9. 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 ratio of the first transition metal to the second transition metal is different in the first and second anodically tinting materials.
10. The electrochromic device of claim 1 , wherein the first and second sublayers of the counter electrode layer are in physical contact with one another.
11. 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.
12. 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.
13. The electrochromic device of claim 1 , further comprising a transparent conductive layer disposed on or over the electrochromic layer and the counter electrode layer.
14. The electrochromic device of claim 13 , wherein the transparent conductive layer comprises a doped indium oxide.
15. The electrochromic device of claim 1 , wherein at least one of the first and second anodically tinting materials comprises nickel, aluminum, and oxygen.
16. The electrochromic device of claim 1 , wherein at least one of the first and second anodically tinting materials comprises nickel, silicon, and oxygen.