Electrochromic Device with Self-forming Ion transfer Layer and Lithium Fluoro-Nitride Electrolyte

• US 20070292606A1
• Filed: 06/06/2007
• Published: 12/20/2007
• Est. Priority Date: 06/20/2006
• Status: Active Grant

• Current Assignee: Eclipse Energy Systems Inc.
• Original Assignee: Eclipse Energy Systems Inc.
• Inventors: Demiryont, Hulya
• Granted Patent: US 7,704,555 B2
• Time in Patent Office: Days
• US Class Current: 427/126.5
• CPC Class Codes: G02F 1/1523 comprising inorganic material
• CPC Class Codes: G02F 1/1524 Transition metal compounds

Abstract

A method of preparing an electrochromic device involves forming multiple layers of selected materials on a substrate in a vacuum processing chamber. A first of these layers is an electrode layer deposited directly on the substrate and used for making contact to a subsequently deposited precursor film, preferably tungsten oxide, from which an electrochromic layer is formed by lithium loading in the presence of ionized nitrogen. This not only forms the electrochromic layer by diffusion of the lithium into the tungsten oxide, but also forms a thin lithium nitride ion transfer layer on the then exposed surface. Subsequently, a lithium fluoro-nitride electrolyte layer is formed on the ion transfer layer by evaporation from a lithium fluoride source in the presence of ionized nitrogen. An ion storage layer, which may be a vanadium oxide and a transparent second electrode layer are subsequently vacuum deposited.

Claims

1. ) A method of making an electrochromic device in which a selected mobile ionic species is selectively movable through an electrolyte layer interposed between an electrochromic layer and an ion storage layer, the method comprising the sequentially executed steps of:

providing, in an evacuated vacuum processing chamber, a substrate having a first electrode layer disposed thereon;

depositing onto the first electrode layer an electrochromic precursor film comprising a metal oxide selected for its capacity to have the selected mobile species diffused thereinto;

providing a source of the mobile ionic species while providing inflow of a selected gas adjacent the substrate, the gas selected to react with the mobile ionic species while the mobile ionic species diffuses into the metal oxide film to thereby form the electrochromic layer from the electrochromic precursor film and to simultaneously form an ion transfer layer on an exposed surface of the electrochromic layer;

forming, on the ion transfer film, an electrolyte layer;

depositing an ion storage film onto the electrolyte film; and

depositing a second, transparent, electrode onto the ion storage film; and

opening the vacuum processing chamber.

2. ) The method of claim 1 wherein the substrate and the first electrode layer are both transparent, and wherein at least one metal contact is electrically connected to the first electrode layer prior to providing, in the vacuum chamber, the substrate having the first electrode layer thereon.

3. ) The method of claim 1 wherein the selected mobile ionic species comprises lithium.

4. ) The method of claim 1 wherein the metal oxide selected for its capacity to have the selected mobile species diffused thereinto is an oxide of one of tungsten, molybdenum, titanium, tantalum and niobium.

5. ) The method of claim 1 wherein the selected gas comprises ionized nitrogen.

6. ) The method of claim 1 wherein the selected gas is nitrogen and the ion transfer film comprises lithium nitride.

7. ) The method of claim 1 wherein the electrolyte film is a lithium fluoro-nitride.

8. ) The method of claim 1 wherein the ion storage film comprises an oxide of at least one of vanadium, cobalt, iridium, manganese, nickel, praseodymium and cerium.

9. ) The method of claim 1 wherein the second electrode comprises a transparent conductive oxide layer having a metal layer deposited thereon.

10. ) The method of claim 1 wherein all of the depositing steps are carried out by one of electron beam evaporation and vapor deposition from a heated crucible.

11. ) A method of making an electrochromic device having an ion transfer layer disposed between an electrochromic layer and an electrolyte layer so that a mobile ionic species passes through the ion transfer and electrolyte layers when moving between the electrochromic layer and an ion storage layer during operation of the device, the method comprising the steps of:

depositing, on a substrate disposed in an evacuated vacuum processing chamber, an electrochromic precursor film comprising an oxide selected for its capacity to have the selected mobile species diffused thereinto;

providing a source of the mobile species while also providing inflow of a selected gas adjacent the substrate, the gas selected to react with the mobile species while the mobile species diffuses into the precursor oxide film and to thereby form the electrochromic layer and deposit the ion transfer layer on an exposed surface thereof, the gas introduced at a pressure in excess of a background pressure of one of oxygen and hydroxide in the processing chamber;

depositing the electrolyte layer; and

depositing the ion storage layer.

12. ) The method of claim 11 wherein the mobile ionic species is lithium and the selected gas is nitrogen.

13. ) The method of claim 11 wherein at least a portion of the selected gas is ionized during the inflow thereof.

14. ) The method of claim 11 wherein the electrochromic precursor layer comprises an oxide of one of tungsten, molybdenum, titanium, tantalum and niobium.

15. ) The method of claim 11 wherein the electrolyte layer consists of lithium, fluorine and nitrogen.

16. ) A method of making a lithium-fluoro-nitride electrolyte layer for use in an electrical device, the method comprising the steps of:

providing, in an evacuated vacuum processing chamber, a substrate having at least one thin film layer disposed thereon, the at least one thin film comprising at least an electronic conductor film;

providing a source of lithium fluoride vapor in the vacuum deposition chamber;

providing a source of ionized nitrogen interposed between the source of lithium fluoride vapor and the substrate so as to deposit on the substrate the lithium-fluoro-nitride electrolyte layer.

17. ) The method of claim 16 wherein the at least one thin film layer disposed on the substrate comprises the electronic conductor film abutting the substrate and a metal oxide film vacuum deposited directly on the electronic conductor film, the metal oxide selected for its capacity to have a selected mobile ion species diffused thereinto.

18. ) The method of claim 16 wherein the step of providing a source of lithium fluoride vapor comprises electron beam evaporation of lithium fluoride.

19. ) The method of claim 16 wherein the ionized nitrogen is introduced at a pressure in excess of a background pressure of one of oxygen and hydroxide in the processing chamber.