Fabrication of electrochromic devices
Electrochromic devices and methods may employ the addition of a defect-mitigating insulating layer which prevents electronically conducting layers and/or electrochromically active layers from contacting layers of the opposite polarity and creating a short circuit in regions where defects form. In some embodiments, an encapsulating layer is provided to encapsulate particles and prevent them from ejecting from the device stack and risking a short circuit when subsequent layers are deposited. The insulating layer may have an electronic resistivity of between about 1 and 10 8 Ohm-cm. In some embodiments, the insulating layer contains one or more of the following metal oxides: aluminum oxide, zinc oxide, tin oxide, silicon aluminum oxide, cerium oxide, tungsten oxide, nickel tungsten oxide, and oxidized indium tin oxide. Carbides, nitrides, oxynitrides, and oxycarbides may also be used.
1. A method of fabricating an electrochromic device, the method comprising:
(a) forming a first electrochromic layer of the electrochromic device on a substrate, the first electrochromic layer comprising tungsten oxide;
(b) after (a), performing a first particle removal operation to remove particles from the first electrochromic layer;
(c) after (b), forming a second layer of the electrochromic device, the second layer comprising a material selected from the group consisting of cerium, titanium, aluminum, zinc, tin, silicon aluminum, tungsten, nickel tungsten, tantalum, oxidized indium tin, oxides thereof, nitrides thereof, carbides thereof, oxynitrides thereof, oxycarbides thereof, and combinations thereof;
(d) after (c), performing a second particle removal operation on a surface of the substrate; and
(e) after (d), completing fabrication of the electrochromic device.
2. The method of claim 1 , wherein at least one of the first and second particle removal operations comprises contact cleaning the substrate.
3. The method of claim 2 , wherein the contact cleaning uses static attraction and/or adhesion to remove the particles.
4. The method of claim 2 , wherein the contact cleaning comprises contacting the substrate with at least one roller, strip, or brush.
5. The method of claim 1 , wherein at least one of the first and second particle removal operations comprises applying acoustic energy to the substrate.
6. The method of claim 5 , wherein the acoustic energy is ultrasonic, supersonic, or megasonic.
7. The method of claim 6 , wherein the acoustic energy is ultrasonic.
8. The method of claim 1 , wherein at least one of the first and second particle removal operations comprises applying fluid to the substrate.
9. The method of claim 8 , wherein the fluid comprises carbon dioxide.
10. The method of claim 8 , wherein the fluid is sprayed onto the substrate.
11. The method of claim 1 , wherein the first particle removal operation removes the particles from the surface of the substrate, thereby forming one or more gaps where the particles were previously positioned in the first electrochromic layer of the electrochromic device, wherein the second layer of the electrochromic device is formed on the first electrochromic layer of the electrochromic device, thereby at least partially filling the one or more gaps.
12. The method of claim 1 , further comprising performing a third particle removal operation, wherein the third particle removal operation is performed on the surface of the substrate prior to (a).
13. The method of claim 12 , wherein (a) is performed immediately after the third particle removal operation.
14. The method of claim 13 , wherein the second layer of the electrochromic device is formed directly on the first electrochromic layer of the electrochromic device, without any intervening layers.
15. The method of claim 1 , wherein the second layer of the electrochromic device is formed directly on the first electrochromic layer of the electrochromic device, without any intervening layers.
16. The method of claim 1 , wherein the second layer of the electrochromic device comprises superstoichiometric oxygen.
17. A method of fabricating an electrochromic device, the method comprising:
(a) forming a first electrochromic layer of the electrochromic device on a substrate;
(b) after (a), performing a first particle removal operation to remove particles from the first electrochromic layer of the electrochromic device;
(c) after (b), forming a second layer of the electrochromic device;
(d) after (c), performing a second particle removal operation on a surface of the substrate; and
(e) after (d), completing fabrication of the electrochromic device,
wherein the first particle removal operation removes the particles from the first electrochromic layer of the electrochromic device, thereby forming one or more gaps where the particles were previously positioned in the first electrochromic layer of the electrochromic device, wherein the second layer of the electrochromic device is formed on the first electrochromic layer of the electrochromic device, thereby at least partially filling the one or more gaps.
18. A method of fabricating an electrochromic device, the method comprising:
(a) forming a first electrochromic layer of the electrochromic device on a substrate;
(b) after (a), performing a first particle removal operation to remove particles from the first electrochromic layer;
(c) after (b), forming a second layer of the electrochromic device;
(d) after (c), performing a second particle removal operation on a surface of the substrate; and
(e) after (d), completing fabrication of the electrochromic device,
wherein at least one of the first and second particle removal operations comprises contact cleaning without contacting the substrate with a brush while delivering fluid.