Electrochromic devices
Conventional electrochromic devices frequently suffer from poor reliability and poor performance. Improvements are made using entirely solid and inorganic materials. Electrochromic devices are fabricated by forming an ion conducting electronically-insulating interfacial region that serves as an IC layer. In some methods, the interfacial region is formed after formation of an electrochromic and a counter electrode layer. The interfacial region contains an ion conducting electronically-insulating material along with components of the electrochromic and/or the counter electrode layer. Materials and microstructure of the electrochromic devices provide improvements in performance and reliability over conventional devices. In various embodiments, a counter electrode is fabricated to include a base anodically coloring material and one or more additives.
1. A method of fabricating an electrochromic device, the method comprising:
(a) forming a cathodically coloring layer comprising a cathodically coloring electrochromic material;
(b) forming an anodically coloring layer comprising an anodically coloring electrochromic material and one or more additives, wherein the cathodically coloring layer and the anodically coloring layer are in contact with one another to form a stack;
(c) exposing the stack to lithium; and
(d) heating the stack to form an ionically conducting and electrically insulating material at an interface between the cathodically coloring layer and the anodically coloring layer.
2. The method of claim 1 , wherein (a) comprises forming a superstoichiometric oxygenated form of the cathodically coloring electrochromic material.
3. The method of claim 1 , wherein the cathodically coloring electrochromic material comprises at least one metal oxide selected from the group consisting of: tungsten oxide, molybdenum oxide, niobium oxide, titanium oxide, vanadium oxide, and combinations thereof.
4. The method of claim 3 , wherein the cathodically coloring electrochromic material comprises tungsten oxide mixed with at least one metal oxide selected from the group consisting of: molybdenum oxide, titanium oxide, and vanadium oxide.
5. The method of claim 4 , wherein the cathodically coloring electrochromic material comprises tungsten oxide mixed with molybdenum oxide and titanium oxide.
6. The method of claim 1 , wherein (a) comprises forming a superstoichiometric oxygenated form of the anodically coloring electrochromic material.
7. The method of claim 1 , wherein the anodically coloring electrochromic material comprises at least one metal oxide selected from the group consisting of: cobalt oxide, chromium oxide, iron oxide, iridium oxide, manganese oxide, nickel oxide, rhodium oxide, ruthenium oxide, vanadium oxide, and combinations thereof.
8. The method of claim 7 , wherein the anodically coloring electrochromic material comprises nickel oxide, and wherein the additives comprise tungsten and tantalum.
9. The method of claim 7 , wherein the anodically coloring electrochromic material comprises nickel oxide, and wherein the additives comprise tungsten and niobium.