Electrochromic display device

• US 20060132885A1
• Filed: 01/30/2004
• Published: 06/22/2006
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: Ntera Incorporated (Ntera Holdings Incorporated)
• Original Assignee: Ntera Incorporated (Ntera Holdings Incorporated)
• Inventors: Bach, Udo, Pichot, Francois, McAtamney, Colm
• Granted Patent: US 7,460,289 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 2001/1536 additional, e.g. protective, layer inside the cell
• CPC Class Codes: G02F 2001/1552 Inner electrode, e.g. the electrochromic layer being sandwiched between the inner electrode and the support substrate
• CPC Class Codes: G02F 2001/1555 Counter electrode

Abstract

The invention concerns an electrochromic device comprising a single supporting substrate (1) on which are disposed a working electrode (6) which is electrochromic per se and/or bears an electrochromic material on at least a portion thereof; a counter electrode (3); and a layer of an electrically insulating material (4) separating the electrodes; wherein said electrochromic material has a major surface at least a portion of which forms at least a portion of an external surface of the device. The new device allows deposition of electrochromic coatings on a variety of substrates which need not be transparent.

Claims

1. An electrochromic device comprising a single supporting substrate on which are disposed:

(a) a working electrode comprising a porous layer of an electrically conducting or semiconducting material, the working electrode comprising material which is electrochromic per se and/or at least a portion of said working electrode bearing electrochromic material;

(b) a counter electrode comprising a porous layer of an electrically conducting or semiconducting material;

(c) a layer of an electrically insulating material which is ion-permeable and which separates the working electrode and the counter electrode layers;

 

wherein said electrochromic material has a major surface at least a portion of which forms at least a portion of an external surface of the device.

2. A device according to claim 1, wherein substantially all of said major surface forms a portion of the external surface of the device.

3. A device according to claim 1, wherein said working electrode has a major surface which is electrochromic per se.

4. A device according to claim 1, wherein said working electrode has a major surface at least a portion of which bears electrochromic material.

5. A device according to claim 4, wherein said electrochromic material substantially covers said major surface of said working electrode.

6. A device according to claim 1, wherein the working electrode, counter electrode and insulating layers are substantially parallel;

and/or wherein the working electrode, counter electrode and insulating layers are substantially coextensive with one another.

7. A device according to claim 1, wherein at least a portion of the working electrode is laterally offset from the counter electrode.

8. A device according to claim 1, wherein the supporting substrate is formed from a transparent or non-transparent material.

9. A device according to claim 8, wherein the substrate is formed from glass or metal or a ceramic or plastics material.

10. A device according to claim 8, wherein the supporting substrate bears an electrically conducting coating on at least a portion of the internal surface thereof.

11. A device according to claim 10, wherein the electrically conducting coating comprises a doped metal oxide, preferably tin oxide doped with fluorine or antimony, or indium oxide doped with tin, or a conducting polymer or metal.

12. A device according to claim 1, wherein the intrinsic sheet resistance of the material of the working electrode and/or the counter electrode is less than 10,000 ohms per square.

13. A device according to claim 1, wherein the working and/or counter electrodes comprise an electrically conducting material comprising nanoparticles of a metal oxide selected from any of the following:

(a) SnO₂ doped with F, Cl, Sb, P, As or B;

(b) ZnO doped with Al, In, Ga, B, F, Si, Ge, Ti, Zr or Hf;

(c) In₂O₃ doped with Sn;

(d) CdO;

(e) ZnSnO₃, Zn₂In₂O₅, In₄Sn₃O₁₂, GaInO₃ or MgIn₂O₄;

(f) Fe₂O₃ doped with Sb;

(g) TiO₂/WO₃ or TiO₂/MoO₃ systems; and

(h) Fe₂O₃/Sb or SnO₂/Sb systems;

preferably SnO₂ doped with Sb.

14. A device according to claim 1, wherein the working and/or counter electrode comprise an electrically semiconducting material comprising nanoparticles of a metal oxide selected from any of the following:

TiO₂, ZrO₂, HfO₂, CrO₃, MoO₃, WO₃, VO, NbO, SnO₂, TaO, AgO, ZnO, SrO, FeO, Fe₂O₃ or NiO, or a perovskite thereof, preferably TiO₂, WO₃, MoO₃, ZnO or SnO₂.

15. A device according to claim 3, wherein the electrochromic material of the working electrode is a metal oxide selected from WO₃ and TiO₂ or a doped metal oxide selected from antimony or fluorine doped tin oxide and tin doped indium oxide.

16. A device according to claim 4, wherein the electrochromic material is selected from viologens and polymers and mixtures thereof.

17. A device according to claim 1, further comprising an ion-conducting medium.

18. A device according to claim 1, wherein the electrically insulating layer comprises an ion-conducting medium.

19. A device according to claim 1, wherein the electrically insulating material is porous and each of the porous layers is at least partially sealed, and the ion-conducting medium comprises a liquid electrolyte which at least partially fills the pores of the electrodes and the insulating material.

20. A device according to claim 1, further comprising a transparent cover at least partially exposing said electrochromic material and a sealing material sealing said cover to said electrochromic device.

21. A device according to claim 20, wherein said sealing material seals said cover to said supporting substrate.

22. A device according to claim 19, wherein the electrically insulating material comprises a metal oxide selected from SiO₂, Al₂O₃, ZrO and MgO, or TiO₂ in the rutile form passivated with SiO₂.

23. A device according to claim 1, further comprising an electrical current supporting layer interposed between the working electrode and the electrically insulating layers.

24. A device according to claim 23, wherein the electrical current supporting layer comprises indium oxide doped with tin or tin oxide doped with fluorine, or a conducting polymer selected from polythiophenes, polypyrroles and polyviologens.

25. A display comprising one or more devices according to claim 1.

26. A display according to claim 25, comprising a plurality of devices connected in series.

27. Use of a device according claim 1 in an active matrix or passive matrix or in direct drive configurations.