FABRICATION OF LOW DEFECTIVITY ELECTROCHROMIC DEVICES

• US 20110211247A1
• Filed: 05/11/2011
• Published: 09/01/2011
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: View Incorporated
• Original Assignee: Soladigm, Inc.
• Inventors: Scobey, Mike, Dixon, Jeremy, Kurman, Eric, Wang, Zhongchun, Rozbicki, Robert, Kozlowski, Mark, Pradhan, Anshu
• Granted Patent: US 8,243,357 B2
• Time in Patent Office: Days
• US Class Current: 359/275
• CPC Class Codes: B05D 5/06 to obtain multicolour or other optical effects B05D5/02 takes precedence
• CPC Class Codes: B23K 20/10 making use of vibrations, e.g. ultrasonic welding
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 2217/94 Transparent conductive oxide layers [TCO] being part of a multilayer coating
• CPC Class Codes: C09K 2211/183 of the refractory metals, i.e. Ti, V, Cr, Zr, Nb, Mo, Hf, Ta or W
• CPC Class Codes: C09K 2211/187 of the iron group metals, i.e. Fe, Co or Ni
• CPC Class Codes: C09K 9/00 Tenebrescent materials, i.e. materials for which the range of wavelengths for energy absorption is changed as a result of excitation by some form of energy
• CPC Class Codes: C23C 10/28 using solids, e.g. powders, pastes
• CPC Class Codes: C23C 14/021 Cleaning or etching treatments
• CPC Class Codes: C23C 14/022 by means of bombardment with energetic particles or radiation
• CPC Class Codes: C23C 14/024 Deposition of sublayers, e.g. to promote adhesion of the coating C23C14/027 takes precedence
• CPC Class Codes: C23C 14/046 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/085 of iron group metals
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/14 Metallic material, boron or silicon
• CPC Class Codes: C23C 14/185 by cathodic sputtering
• CPC Class Codes: C23C 14/3407 Cathode assembly for sputtering apparatus, e.g. Target
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence
• CPC Class Codes: C23C 14/58 : After-treatment
• CPC Class Codes: C23C 14/5806 : Thermal treatment
• CPC Class Codes: C23C 14/5853 : Oxidation
• CPC Class Codes: G02F 1/1524 : Transition metal compounds
• CPC Class Codes: G02F 1/1525 : characterised by a particular ion transporting layer, e.g. electrolyte
• CPC Class Codes: G02F 1/153 : Constructional details
• CPC Class Codes: G02F 1/1533 : structural features not otherwise provided for
• CPC Class Codes: G02F 1/155 : Electrodes
• CPC Class Codes: G02F 2001/1536 : additional, e.g. protective, layer inside the cell

Abstract

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.

Claims

1. An electrochromic window comprising:

(a) an architectural glass substrate; and

(b) a electrochromic stack disposed on said substrate, the stack comprising a tungsten oxide electrochromic layer and a nickel tungsten oxide counter electrode layer;

wherein the electrochromic window has fewer than about 0.045 total visible defects per square centimeter in any region of electrochromic active area.

2. The electrochromic window of claim 1, wherein the electrochromic layer comprises WO_x, wherein x is less than 3.0 and at least 2.7.

3. The electrochromic window of claim 1, wherein the tungsten oxide has a substantially nanocrystalline morphology.

4. The electrochromic window of claim 1, wherein the electrochromic layer has a thickness of between about 200 nm and about 700 nm.

5. The electrochromic window of claim 1, wherein the electrochromic layer and the counter electrode layer each comprise lithium ions.

6. The electrochromic window of claim 1, wherein the counter electrode layer has a thickness of between about 150 nm and about 350 nm.

7. The electrochromic window of claim 1, wherein the ratio of thicknesses of the electrochromic layer to the counter electrode layer is between about 1.7:

1 and 2.3;

1.

8. The electrochromic window of claim 1, further comprising a first layer of transparent conductive oxide in electrical contact with the electrochromic layer and a second layer of transparent conductive oxide in electrical contact with the counter electrode layer.

9. The electrochromic window of claim 8, wherein each layer of transparent conductive oxide has a sheet resistance of between about 5 ohms/square and about 30 ohms/square.

10. The electrochromic window of claim 9, wherein each layer of transparent conductive oxide has substantially the same sheet resistance.

11. The electrochromic window of claim 1, comprising fewer than about 0.04 visible pinhole defects per square centimeter of the electrochromic window.

12. The electrochromic window of claim 1, comprising fewer than about 0.005 visible short-type defects per square centimeter of the electrochromic window.

13. The electrochromic window of claim 1, comprising a number of non-visible short-type defects that produce a leakage current of less than about 5 μ

A/cm² at ±

2V bias of the electrochromic window.