Electrochromic devices

Abstract

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.

What is claimed is: 
     
         1 . An electrochromic device precursor comprising:
 (a) a substrate;   (b) an electrochromic layer comprising a cathodically coloring electrochromic material; and   (c) a counter electrode layer comprising an anodically coloring electrochromic material and one or more additives,
 wherein at least one of the cathodically coloring electrochromic material and the anodically coloring electrochromic material are present in a superstoichiometric oxygenated form at an interface between the electrochromic layer and the counter electrode layer, and 
 wherein the electrochromic device precursor does not comprise an ionically conducting and electronically insulating region between the electrochromic layer and the counter electrode layer. 
   
     
     
         2 . The electrochromic device precursor of  claim 1 , wherein the cathodically coloring electrochromic material is present in the superstoichiometric oxygenated form at the interface between the electrochromic layer and the counter electrode layer. 
     
     
         3 . The electrochromic device precursor 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 electrochromic device precursor 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 electrochromic device precursor of  claim 4 , wherein the cathodically coloring electrochromic material comprises tungsten oxide mixed with molybdenum oxide and titanium oxide. 
     
     
         6 . The electrochromic device precursor of  claim 1 , wherein the anodically coloring electrochromic material is present in the superstoichiometric oxygenated form at the interface between the electrochromic layer and the counter electrode layer. 
     
     
         7 . The electrochromic device precursor 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 electrochromic device precursor of  claim 7 , wherein the anodically coloring electrochromic material comprises nickel oxide, and wherein the additives comprise tungsten and tantalum. 
     
     
         9 . The electrochromic device precursor of  claim 7 , wherein the anodically coloring electrochromic material comprises nickel oxide, and wherein the additives comprise tungsten and niobium. 
     
     
         10 . An apparatus for fabricating electrochromic devices, the apparatus comprising:
 (a) a first deposition station containing one or more targets for forming an electrochromic layer on a substrate when the substrate is positioned in the first deposition station, wherein the electrochromic layer comprises a cathodically coloring electrochromic material;   (b) a second deposition station containing one or more targets for forming a counter electrode layer on a substrate when the substrate is positioned in the second deposition station, wherein the counter electrode layer comprises an anodically coloring electrochromic material and one or more additives; and   (c) a controller containing program instructions for passing the substrate through the first and second deposition stations in a manner that sequentially deposits a stack on the substrate, the stack comprising the electrochromic layer in direct contact with the counter electrode layer, without an ion conducting layer between electrochromic layer and the counter electrode layer, wherein the stack comprises a superstoichiometric oxygenated form of at least one of the cathodically coloring electrochromic material and the anodically coloring electrochromic material at an interface between the electrochromic layer and the counter electrode layer.   
     
     
         11 . The apparatus of  claim 10 , wherein the stack comprises the superstoichiometric oxygenated form of the cathodically coloring electrochromic material at the interface between the electrochromic layer and the counter electrode layer. 
     
     
         12 . The apparatus of  claim 10 , 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. 
     
     
         13 . The apparatus of  claim 12 , 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. 
     
     
         14 . The apparatus of  claim 13 , wherein the cathodically coloring electrochromic material comprises tungsten oxide mixed with molybdenum oxide and titanium oxide. 
     
     
         15 . The apparatus of  claim 10 , wherein the stack comprises the superstoichiometric oxygenated form of the anodically coloring electrochromic material at the interface between the electrochromic layer and the counter electrode layer. 
     
     
         16 . The apparatus of  claim 10 , 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. 
     
     
         17 . The apparatus of  claim 16 , wherein the anodically coloring electrochromic material comprises nickel oxide, and wherein the additives comprise tungsten and tantalum. 
     
     
         18 . The apparatus of  claim 16 , wherein the anodically coloring electrochromic material comprises nickel oxide, and wherein the additives comprise tungsten and niobium.