Fabrication of low defectivity electrochromic devices
Prior electrochromic devices frequently suffer from high levels of defectivity. The defects may be manifest as pin holes or spots where the electrochromic transition is impaired. This is unacceptable for many applications such as electrochromic architectural glass. Improved electrochromic devices with low defectivity can be fabricated by depositing certain layered components of the electrochromic device in a single integrated deposition system. While these layers are being deposited and/or treated on a substrate, for example a glass window, the substrate never leaves a controlled ambient environment, for example a low pressure controlled atmosphere having very low levels of particles. These layers may be deposited using physical vapor deposition.
1. An electrochromic device comprising:
a first transparent conductive layer;
an electrochromic layer comprising a tungsten oxide based electrochromic material doped with one or more materials selected from the group consisting of: molybdenum, vanadium, and titanium;
a counter electrode layer comprising a nickel oxide based counter electrode material doped with tungsten and tantalum; and
a second transparent conductive layer.
2. The electrochromic device of claim 1 , wherein the tungsten oxide based electrochromic material is doped with molybdenum.
3. The electrochromic device of claim 1 , wherein the tungsten oxide based electrochromic material is doped with vanadium.
4. The electrochromic device of claim 1 , wherein the tungsten oxide based electrochromic material is doped with titanium.
5. The electrochromic device of claim 1 , wherein the tungsten oxide based electrochromic material is further doped with lithium, sodium, and/or potassium.
6. The electrochromic device of claim 1 , wherein the first and second transparent conductive layers each have a sheet resistance between about 5 and 30 Ohms per square.
7. The electrochromic device of claim 1 , wherein the first and second transparent conductive layers each comprise a material selected from the group consisting of: a conductive oxide material, a conductive metallic material, a conductive metal nitride, and a conductive composite material.
8. The electrochromic device of claim 7 , wherein at least one of the first and second transparent conductive layers comprise the conductive oxide material, and wherein the conductive oxide material is selected from the group consisting of: indium oxide, indium tin oxide, doped indium oxide, tin oxide, doped tin oxide, zinc oxide, aluminum zinc oxide, doped zinc oxide, ruthenium oxide, and doped ruthenium oxide.
9. The electrochromic device of claim 7 , wherein at least one of the first and second transparent conductive layers comprise the conductive metallic material, and wherein the conductive metallic material is selected from the group consisting of: gold, platinum, silver, aluminum, and a nickel alloy.
10. The electrochromic device of claim 7 , wherein at least one of the first and second transparent conductive layers comprise the conductive metal nitride, and wherein the conductive metal nitride is selected from the group consisting of: titanium nitrides, tantalum nitrides, titanium oxynitrides, and tantalum oxynitrides.
11. The electrochromic device of claim 7 , wherein at least one of the first and second transparent conductive layers comprise the conductive composite material, wherein the conductive composite material comprises (i) conductive ceramic and metal wires, or a conductive pattern, and (ii) a transparent conductive material that overlays the ceramic and metal wires or the conductive pattern, respectively.
12. The electrochromic device of claim 1 , wherein each of the first and second conductive layers has a thickness between about 5 and 10,000 nm.
13. The electrochromic device of claim 12 , wherein each of the first and second conductive layers has a thickness between about 100 and 400 nm.
14. The electrochromic device of claim 1 , further comprising an ion conducting layer, wherein the ion conducting layer comprises a material selected from the group consisting of: a silicate, a silicon oxide, a tungsten oxide, a tantalum oxide, a niobium oxide, and a borate.
15. The electrochromic device of claim 1 , further comprising an ion conducting layer, wherein the ion conducting layer comprises a material selected from the group consisting of: silicon oxide, silicon aluminum oxide, lithium silicon oxide, lithium silicon aluminum oxide, lithium silicate, lithium aluminum silicate, lithium aluminum borate, lithium aluminum fluoride, lithium borate, lithium nitride, lithium zirconium silicate, lithium niobate, lithium borosilicate, and lithium phosphosilicate.
16. The electrochromic device of claim 1 , further comprising an ion conducting layer, wherein the ion conducting layer has a thickness between about 5 and 100 nm.
17. The electrochromic device of claim 1 , wherein the electrochromic layer has a thickness between about 200-700 nm.
18. The electrochromic device of claim 1 , wherein the counter electrode layer has a thickness between about 150 and 350 nm.
19. The electrochromic device of claim 1 , wherein a ratio of thicknesses of the electrochromic layer to the counter electrode layer is between about 1.7:1 and 2.3:1.
20. The electrochromic device of claim 1 , wherein the electrochromic layer has a substantially nanocrystalline morphology and the counter electrode layer has a substantially amorphous morphology.
21. The electrochromic device of claim 1 , wherein the tungsten oxide based electrochromic material and the nickel oxide based counter electrode material each comprise lithium.