Electrochromic cathode materials
Various embodiments herein relate to electrochromic devices and electrochromic device precursors, as well as methods and apparatus for fabricating such electrochromic devices and electrochromic device precursors. In certain embodiments, the electrochromic device or precursor may include one or more particular materials such as a particular electrochromic material and/or a particular counter electrode material. In various implementations, the electrochromic material includes tungsten molybdenum oxide. In these or other implementation, the counter electrode material may include nickel tungsten oxide, nickel tungsten tantalum oxide, nickel tungsten niobium oxide, nickel tungsten tin oxide, or another material.
1 . An electrochromic device or an electrochromic device precursor, comprising:
a first electrically conductive layer having a thickness between about 10-500 nm;
an electrochromic layer comprising an electrochromic material comprising tungsten molybdenum oxide having a composition of W 1-x Mo x O y , wherein x is between about 0.05-0.30 and y is between about 2.5-4.5, the electrochromic layer having a thickness between about 100-500 nm;
a counter electrode layer comprising a counter electrode material comprising nickel tungsten oxide, the counter electrode layer having a thickness between about 100-500 nm; and
a second electrically conductive layer having a thickness between about 100-400 nm,
wherein the electrochromic layer and the counter electrode layer are positioned between the first electrically conductive layer and the second electrically conductive layer, and wherein the electrochromic device is all solid state and inorganic.
2 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the electrochromic layer is nanocrystalline.
3 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the electrochromic layer is amorphous.
4 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the counter electrode layer is nanocrystalline.
5 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the counter electrode layer is amorphous.
6 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the counter electrode material comprises nickel tungsten tantalum oxide.
7 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the counter electrode material comprises nickel tungsten niobium oxide.
8 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the counter electrode material comprises nickel tungsten tin oxide.
9 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the electrochromic layer, the counter electrode layer, and the second electrically conductive layer were all formed through sputtering.
10 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the electrochromic device or electrochromic device precursor does not include a homogenous layer of ion conducting, electronically insulating material between the electrochromic layer and the counter electrode layer.
11 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the electrochromic material is in physical contact with the counter electrode material.
12 . The electrochromic device or electrochromic device precursor of claim 1 , wherein at least one of the electrochromic layer and the counter electrode layer comprise two or more layers or portions, one of the layers or the portions being superstoichiometric with respect to oxygen.
13 . The electrochromic device or electrochromic device precursor of claim 12 , wherein either:
(a) the electrochromic layer comprises the two or more layers, and the layer that is superstoichiometric with respect to oxygen being in contact with the counter electrode layer, or
(b) the counter electrode layer comprises the two or more layers, and the layer that is superstoichiometric with respect to oxygen being in contact with the electrochromic layer.
14 . The electrochromic device or electrochromic device precursor of claim 12 , wherein either:
(a) the electrochromic layer comprises the two or more layers or portions, the two or more layers or portions together forming the electrochromic layer as a graded composition layer, and the layer or portion of the electrochromic layer that is superstoichiometric with respect to oxygen being in contact with the counter electrode layer, or
(b) the counter electrode layer comprises the two or more layers or portions, the two or more layers or portions together forming the counter electrode layer as a graded composition layer, and the layer or portion of the counter electrode layer that is superstoichiometric with respect to oxygen being in contact with the electrochromic layer.
15 . The electrochromic device or electrochromic device precursor of claim 1 , further comprising a material that is ion conducting and substantially electronically insulating that is formed in situ at an interface between the electrochromic layer and the counter electrode layer.
16 . The electrochromic device or electrochromic device precursor of claim 1 , further comprising an ion conducting layer comprising a material selected from the group consisting of: lithium silicate, lithium aluminum silicate, lithium oxide, lithium tungstate, lithium aluminum borate, lithium borate, lithium zirconium silicate, lithium niobate, lithium borosilicate, lithium phosphosilicate, lithium nitride, lithium oxynitride, lithium aluminum fluoride, lithium phosphorus oxynitride (LiPON), lithium lanthanum titanate (LLT), lithium tantalum oxide, lithium zirconium oxide, lithium silicon carbon oxynitride (LiSiCON), lithium phosphate, lithium titanium phosphate, lithium germanium vanadium oxide, lithium zinc germanium oxide, and combinations thereof.
17 . The electrochromic device or electrochromic device precursor of claim 16 , wherein the ion conducting layer has a thickness between about 5-100 nm.
18 . The electrochromic device or electrochromic device precursor of claim 16 , wherein the ion conducting layer comprises a material selected from the group consisting of: lithium silicate, lithium aluminum silicate, lithium zirconium silicate, lithium borosilicate, lithium phosphosilicate, lithium phosphorus oxynitride (LiPON), lithium silicon carbon oxynitride (LiSiCON), and combinations thereof.
19 . The electrochromic device or electrochromic device precursor of claim 1 , wherein x is between about 0.1 and 0.25.
20 . The electrochromic device or electrochromic device precursor of claim 1 , wherein x is between about 0.15 and 0.2.
21 . The electrochromic device or electrochromic device precursor of claim 12 , wherein the layer or portion that is superstoichiometric with respect to oxygen has an excess of oxygen.
22 . The electrochromic device or electrochromic device precursor of claim 1 , further comprising an intermediate layer positioned between the electrochromic layer and the counter electrode layer, wherein the intermediate layer comprises a tungsten oxide that is superstoichiometric with respect to oxygen.
23 . The electrochromic device or electrochromic device precursor of claim 22 , wherein the tungsten oxide does not contain molybdenum.
24 . The electrochromic device or electrochromic device precursor of claim 22 , wherein the tungsten oxide comprises molybdenum.
25 . The electrochromic device or electrochromic device precursor of claim 22 , wherein the tungsten oxide does not comprise molybdenum and is amorphous.
26 . The electrochromic device or electrochromic device precursor of claim 1 , wherein the counter electrode layer comprises a first sublayer and a second sublayer, wherein the first sublayer comprises a first composition of nickel tungsten oxide and the second sublayer comprise a second composition of nickel tungsten oxide, wherein the first composition and second composition are different from one another.
27 . The electrochromic device or electrochromic device precursor of claim 1 , wherein at least a portion of an edge of the first electrically conductive layer is tapered.