Fabrication of low defectivity electrochromic devices

• US 9,664,974 B2
• Filed: 12/22/2009
• Issued: 05/30/2017
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: View Incorporated
• Original Assignee: View Incorporated
• Inventors: Wang, Zhongchun, Pradhan, Anshu, Rozbicki, Robert, Kozlowski, Mark, Kurman, Eric, Scobey, Mike, Dixon, Jeremy
• Primary Examiner(s): BRAYTON, JOHN JOSEPH
• Application Number:
  US12/645,111
• Publication Number:
  US 20100243427A1
• Time in Patent Office: 2,716 Days
• Field of Search: 20429825, 20429826, 2041921-19238, 20429815, 118500
• 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 integrated deposition system comprising:

a plurality of deposition stations arranged in series and operable to pass a transparent substrate from one station to an adjacent station without exposing the transparent substrate to an external environment, wherein the plurality of deposition stations comprise

(i) a first deposition station containing a material source that, during operation, deposits a tungsten oxide based electrochromic layer,

(ii) a second deposition station containing a material source that, during operation, deposits a nickel oxide based counter electrode layer,

(iii) a third deposition station having a lithium metal sputter target comprising between about 90% and about 99% by weight lithium metal, wherein the lithium metal sputter target deposits lithium metal during operation, and

(iv) a fourth deposition station having a material source that, during operation, deposits a transparent conducting oxide layer;

a substrate holder that, during operation, holds the transparent substrate in a substantially vertical orientation while the substrate holder translates through the first, second, third, and fourth deposition stations without exposing the transparent substrate to the external environment during deposition; and

a controller containing program instructions for passing the transparent substrate through the first, second, third, and fourth deposition stations in a manner that deposits on the transparent substrate the tungsten oxide based electrochromic layer, the nickel oxide based counter electrode layer, lithium metal onto at least one of the tungsten oxide based electrochromic layer and the nickel oxide based counter electrode layer, and the transparent conducting oxide layer to form a stack of an inorganic and solid state electrochromic device on the transparent substrate, the program instructions providing that the lithium metal is deposited in an amount that is at least sufficient to compensate blind charge in the inorganic and solid state electrochromic device and an additional amount of 1.5 to 2.5 times by mass;

wherein the plurality of deposition stations deposit, during operation, material layers of the inorganic and solid state electrochromic device on the transparent substrate fabricating an electrochromic window.

2. The system of claim 1, further comprising one or more load locks for passing the transparent substrate between an external environment and the integrated deposition system.

3. The system of claim 1 comprising at least one additional lithium deposition station having another lithium metal sputter target for depositing lithium.

4. The system of claim 1, further comprising at least one slit valve operable to permit isolation of the third deposition station from one or more other deposition stations of the plurality of deposition stations.

5. The system of claim 1,

wherein the plurality of deposition stations further comprises another deposition station containing a material source for depositing an ion conducting layer, and

wherein the program instructions for passing the transparent substrate through the first, second, third, and fourth deposition stations further includes instructions for sequentially depositing the ion conducting layer to form a stack in which the ion conducting layer separates the tungsten oxide based electrochromic layer and the nickel oxide based counter electrode layer.

6. The system of claim 5, wherein the ion conducting layer is inorganic and solid-state.

7. The system of claim 1, wherein the transparent substrate passes sequentially through the first, second, third, and fourth deposition stations.

8. The system of claim 1, wherein the transparent substrate passes sequentially through the second, first, third, and fourth deposition stations.

9. The system of claim 1, wherein the system is further configured to fabricate the electrochromic device with a leakage current less than about 5 μ

A/cm².

10. The system of claim 1, wherein the material sources in the first, second, third, and fourth deposition stations, including the lithium metal sputter target, are configured to deposit materials on only one side of the transparent substrate.

11. The system of claim 1, wherein the internal environment of the plurality of deposition stations is configured to produce fewer than 350 particles of size 0.1 micrometers or larger per m³.

12. The system of claim 1, wherein the substrate holder is further configured to hold one or more transparent substrates having a thickness of between about 3 mm and 9 mm.

13. The system of claim 1, wherein the substrate holder comprises a pallet configured to hold the transparent substrate about a perimeter of the transparent substrate.

14. The system of claim 1, further comprising a track, wherein the substrate holder travels along the track through first, second, third, and fourth deposition stations.

15. The system of claim 1, wherein the transparent substrate held by the substrate holder is at least about 80 inches by 120 inches.

16. The system of claim 1, wherein the system is configured to hold the transparent substrate at a deposition temperature of up to 350°

C.

17. The system of claim 1, wherein the substrate holder is further configured to hold the transparent substrate having a thickness of between about 0.01 to 10 mm.

18. The system of claim 1, wherein the system is configured to pass the transparent substrate through all of the plurality of deposition stations without exposing the transparent substrate to the external environment.

19. The system of claim 1, wherein the system is operable to fabricate the tungsten oxide based electrochromic layer, an ion conductor layer, and the nickel oxide based counter electrode layer without the substrate leaving the system at any time during sequential deposition through the first, second, third, and fourth deposition stations.

20. The system of claim 17, wherein the substrate holder can accommodate the transparent substrate having a size of up to about 72 inches by 120 inches.

21. The system of claim 1, wherein the lithium metal sputter target is oriented substantially vertical.

22. The system of claim 1, wherein the lithium metal sputter target is cylindrical.

23. The system of claim 1, wherein the transparent substrate passes sequentially through the third deposition station after passing through the fourth, first, and second deposition stations.

24. The system of claim 1, wherein lithium metal is deposited in the third deposition station after deposition of both the tungsten oxide based electrochromic layer in the first deposition station and the nickel oxide based counter electrode layer in the second deposition station.

25. The system of claim 17, wherein the substrate holder can accommodate the transparent substrate having a size of more than 72 inches by 120 inches.