Electrochromic devices

• US 9,261,751 B2
• Filed: 05/02/2012
• Issued: 02/16/2016
• Est. Priority Date: 04/30/2010
• Status: Active Grant

• Current Assignee: View Incorporated
• Original Assignee: View Incorporated
• Inventors: Pradhan, Anshu A., Rozbicki, Robert T.
• Primary Examiner(s): TRA, TUYEN Q
• Application Number:
  US13/462,725
• Publication Number:
  US 20120275008A1
• Time in Patent Office: 1,385 Days
• Field of Search: 359265-275, 345/105
• US Class Current: 1/1
• CPC Class Codes: C03C 2217/91 Coatings containing at least one layer having a composition gradient through its thickness
• 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 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/0084 Producing gradient compositions
• 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 14/14 Metallic material, boron or silicon
• CPC Class Codes: C23C 14/18 on other inorganic substrates
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: C23C 14/3464 using more than one target C23C14/56 takes precedence
• CPC Class Codes: C23C 14/548 Controlling the composition
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence
• CPC Class Codes: G02F 1/1506 caused by electrodeposition, e.g. electrolytic deposition of an inorganic material on or close to an electrode
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 2001/15145 the electrochromic layer comprises a mixture of anodic and cathodic compounds
• CPC Class Codes: G02F 2001/1555 Counter electrode
• CPC Class Codes: H01J 37/3473 Composition uniformity or desired gradient

Abstract

Conventional electrochromic devices frequently suffer from poor reliability and poor performance. Improvements are made using entirely solid and inorganic materials. Electrochromic devices are fabricated by forming an ion conducting electronically-insulating interfacial region that serves as an IC layer. In some methods, the interfacial region is formed after formation of an electrochromic and a counter electrode layer. The interfacial region contains an ion conducting electronically-insulating material along with components of the electrochromic and/or the counter electrode layer. Materials and microstructure of the electrochromic devices provide improvements in performance and reliability over conventional devices.

Claims

1. An EC element comprising a single layer graded composition comprising an EC region, an IC region and a CE region, respectively.

2. The EC element of claim 1 which is all solid-state and inorganic.

3. The EC element of claim 2, comprising:

a) a first transition metal and a second transition metal, wherein the EC region comprises the first transition metal and optionally comprises the second transition metal, wherein the EC region composition comprises a higher mole fraction of the first transition metal compared to the second transition metal;

b) an alkali metal having a maximum mole fraction of the composition in the IC region as compared to the EC region and the CE region; and

c) the second transition metal having its maximum mole fraction, of the composition of any region of the EC element, in the CE region.

4. The EC element of claim 2, comprising:

a) a first transition metal having a maximum concentration, relative to other metals in the EC element, in the EC region;

b) an alkali metal having a maximum concentration, relative to other metals in the EC element, in the IC region; and

c) a second transition metal having its absolute maximum concentration in the CE region of the EC element.

5. The EC element of claim 3 or 4, further comprising oxygen in each of the EC, IC and CE regions.

6. The EC element of claim 2, comprising:

a) a first transition metal oxide which is the primary constituent of the EC region;

b) a mixed transition metal oxide which is the primary constituent of the CE region; and

c) a mixture comprising an alkali metal-containing compound, the first transition metal and the mixed transition metal oxide, said mixture the primary constituent of the IC region.

7. The EC element of claim 6, wherein the mixed transition metal oxide comprises the first transition metal and a second transition metal selected from the group consisting of nickel, tantalum, titanium, vanadium, chromium, cerium, cobalt, copper, iridium, iron, manganese, molybdenum, niobium, palladium, praseodymium, rhodium and ruthenium.

8. The EC element of any one of claims 3-7, wherein the first transition metal is tungsten and the alkali metal is lithium.

9. The EC element of claim 8, wherein the second transition metal is nickel.

10. The EC element of any one of claims 3-7, wherein the EC region is cathodically coloring and the CE region is anodically coloring.

11. The EC element of claim 10, configured to operate by migration of lithium ions from the CE region, through the IC region and into the EC region, or, from the EC region, through the IC region and into the CE region, when a potential is applied across the EC element.

12. The EC element of claim 6, wherein the first transition metal oxide is tungsten oxide and the mixed transition metal oxide is nickel tungsten oxide.

13. An EC device comprising:

a) a first transparent electrode;

b) a second transparent electrode; and

c) the EC element of any one of claims 1-7, 9, 11-12 sandwiched therebetween.

14. The EC device of claim 13, wherein the first and second transparent electrodes comprise tin oxide based materials.

15. The EC device of claim 14, fabricated on a glass substrate.

16. The EC device of claim 15, further comprising a diffusion barrier between the glass substrate and the EC device.

27. The EC element or device of any of claim 1, 17, or 20, wherein an interface between the EC region and the IC region or between the IC region and the CE region has a composition gradient of at least about 20 nm.

28. The EC element or device of any of claim 1, 17, or 20, wherein an interface between the EC region and the IC region or between the IC region and the CE region has a composition gradient of at least about 5% of the total element thickness of the EC element.

17. An EC element which is a single layer graded composition comprising:

d) an EC region comprising primarily tungsten oxide;

e) a CE region comprising primarily nickel tungsten oxide; and

, therebetween,

f) an IC region comprising a mixture of lithium tungstate, tungsten oxide and nickel tungsten oxide.

18. An EC device comprising the EC element of claim 17.

19. The EC device of claim 18, wherein the EC element is sandwiched between two transparent conductive electrodes.

23. The EC element of any one of claims 3-7, 17 and 20, further comprising, abutting one of the EC or the CE face of the EC element, a reflective coating, a thermochromic coating or a photochromic coating.

24. An EC device comprising the EC element of claim 23 sandwiched between two transparent conductive electrodes.

25. The EC device of claim 24, comprising a reflective coating abutting the CE face of the EC element.

26. The EC device of claim 25, configured to operate by migration of lithium ions from the CE region, through the IC region and into the EC region, or, from the EC region, through the IC region and into the CE region, when a potential is applied across the EC element.

20. An EC element which is a single layer graded composition comprising:

a) An EC region comprising a tungsten oxide rich matrix which transitions to a matrix with increasingly more lithium tungstate;

b) an IC region comprising a mixture of lithium tungstate, tungsten oxide and nickel tungsten oxide, the IC region transitioning, moving away from the EC region;

i. from more to less tungsten oxide;

ii. from less to more nickel tungsten oxide; and

iii. having a lithium tungstate rich matrix near a central portion of the IC region; and

c) a CE region which transitions, moving away from the IC region, from more to less lithium tungstate to a nickel tungsten oxide rich matrix.

21. An EC device comprising the EC element of claim 20.

22. The EC device of claim 20, wherein the EC element is sandwiched between two transparent conductive electrodes.