Method for manufacturing structural color filter by electrodeposition of metal/dielectric layer/metal

Patent metadata

Field	Value
Publication number	US-11526049-B2
Application number	US-202016883727-A
Country	US
Kind code	B2
Filing date	May 26, 2020
Priority date	May 24, 2019
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A method of forming a structural color filter includes: depositing a first metal layer on a surface of a substrate by applying an electric potential to the substrate; depositing a first dielectric layer on the first metal layer by contacting the first metal layer with a second electrolyte; and depositing a second metal layer on the first dielectric layer. The surface of the substrate is in contact with a first electrolyte; the first electrolyte comprises a first precursor, an electrochemical reaction of the first precursor at the surface of the substrate is driven by the electric potential; the depositing the first metal layer on the surface of the substrate is performed at a temperature of less than or equal to 50° C. The second electrolyte comprises a second precursor of a first dielectric material of the first dielectric layer.

First claim

What is claimed is:

1. A method of forming a structural color filter comprising:
depositing a first metal layer on a surface of a substrate by applying an electric potential to the substrate, wherein the surface of the substrate is in contact with a first electrolyte; the first electrolyte comprises a first precursor, an electrochemical reaction of the first precursor at the surface of the substrate is driven by the electric potential; the depositing the first metal layer on the surface of the substrate is performed at a temperature of less than or equal to 50° C.; and
depositing a first dielectric layer on the first metal layer by contacting the first metal layer with a second electrolyte, wherein the second electrolyte comprises a second precursor of a first dielectric material of the first dielectric layer, and the first metal layer is sandwiched between the first dielectric layer and the substrate; and
depositing a second metal layer on the first dielectric layer, wherein the first dielectric layer is sandwiched between the first metal layer and the second metal layer;
wherein the first electrolyte has a pH of less than or equal to 3.

2. The method of claim 1 , further comprising:
depositing a second dielectric layer on the second metal layer, wherein the second metal layer is sandwiched between the first dielectric layer and the second dielectric layer.

3. The method of claim 1 , wherein the first metal layer comprises a metal selected from the group consisting of: gold (Au), copper (Cu), aluminum (Al), silver (Ag), and combinations thereof.

4. The method of claim 1 , wherein each of the depositing the first metal layer on the surface of the substrate, the depositing the first dielectric layer on the first metal layer, and the depositing the second metal layer on the first dielectric layer is performed in an environment having an ambient pressure.

5. The method of claim 1 , wherein the depositing the second metal layer on the first dielectric layer comprises contacting the first dielectric layer with a third electrolyte, wherein the third electrolyte comprises a third precursor, and the third electrolyte is basic having a pH of greater than or equal to 10.

6. The method of claim 1 , wherein the depositing the second metal layer on the first dielectric layer comprises depositing the second metal layer by an electroless deposition process.

7. The method of claim 6 , wherein the second metal layer comprises silver and the electroless deposition process comprises exposing a surface of the first dielectric layer to a silver precursor solution and a silver activator solution, exposing the surface of the first dielectric layer to a sensitizing solution, and exposing the surface of the first dielectric layer to a reducer solution.

8. The method of claim 1 , further comprising:
forming a second dielectric layer on the second metal layer, and forming a third metal layer on the second dielectric layer, wherein the first metal layer and the third metal layer have a same first thickness, the second metal layer, the first dielectric layer, and the second dielectric layer have a same second thickness, and the first thickness and the second thickness are different.

9. The method of claim 8 , further comprising:
forming a third dielectric layer adjacent to the first metal layer, wherein the third dielectric layer has a first exposed surface; and
forming a fourth dielectric layer adjacent to the third metal layer, wherein the fourth dielectric layer has a second exposed surface,
wherein the third dielectric layer and the first dielectric layer are formed on two opposing sides of the first metal layer, and the fourth dielectric layer and the second dielectric layer are formed on two opposing sides of the third metal layer.

10. The method of claim 8 , wherein the first metal layer, the first dielectric layer, the second metal layer, the second dielectric layer, and the third metal layer forms a stack, and the method further comprises separating the stack from the substrate and grinding the stack into particles.

11. The method of claim 1 , wherein the first precursor comprises a metal selected from the group consisting of: gold (Au), copper (Cu), aluminum (Al), silver (Ag), and combinations thereof, and the first precursor is selected from the group consisting of: chloroauric acid, potassium dicyanoaurate, copper-citrate, copper tartrate, copper glycerol, silver cyanide, aluminum chloride, silver nitrate, silver diammine complex, and combinations thereof.

12. The method of claim 1 , wherein a material of the first dielectric layer is selected from the group consisting of: cuprous oxide (Cu 2 O), amorphous silicon (a-Si), titanium oxide (TiO x ), zinc oxide (ZnO), and combinations thereof, and the second precursor is selected from the group consisting of: copper sulfate, trichlorosilane, zinc nitrate, and titanium powder.

13. The method of claim 1 , wherein the depositing the first metal layer comprises applying a current at a current density of greater than or equal to 0.05 mA/cm 2 and less than or equal to 1 mA/cm 2 .

14. The method of claim 1 , wherein the depositing the first dielectric layer comprises applying a current at a current density of greater than or equal to 0.05 mA/cm 2 and less than or equal to 0.1 mA/cm 2 .

15. The method of claim 1 , wherein the depositing the first dielectric material layer and the depositing of the first metal layer are performed in a three-electrode cell comprising a reference electrode, and the method further comprises monitoring one or more parameters selected from the group consisting of: nucleation of material, material thickness, and rate of deposition of material, via the reference electrode.

16. The method of claim 1 , wherein the first metal layer has a surface roughness of less than or equal to 25% of a thickness of the first metal layer.

17. The method of claim 1 , wherein the substrate is an electrically conductive substrate, and the electrically conductive substrate is transparent to visible light and is flexible or rigid.

18. The method of claim 1 , wherein the first metal layer has a first thickness of greater than or equal to 5 nm and less than or equal to 50 nm, the second metal layer has a second thickness of greater than or equal to 5 nm and less than or equal to 50 nm, and the second thickness is greater than or equal to the first thickness.

19. A method of forming a structural color filter comprising:
depositing a first metal layer on a surface of a substrate in contact with a first electrolyte by applying an electric potential to the substrate, wherein the first electrolyte comprises a first precursor and has a pH of less than or equal to 3, the electric potential drives an electrochemical reaction of the first precursor at the surface of the substrate, the depositing the first metal layer on the surface of the substrate is performed at a temperature of less than or equal to 50° C., and the first metal layer film comprises a metal selected from the group consisting of: gold (Au), copper (Cu), aluminum (Al), silver (Ag), and combinations thereof;
depositing a dielectric layer on the first metal layer by contacting the first metal layer with a second electrolyte, wherein the second electrolyte comprises a second precursor of a dielectric material of the dielectric layer and has a pH of greater than or equal to 10; and
depositing a second metal layer on the dielectric layer by contacting the dielectric layer with a third electrolyte and applying an electric potential to the substrate, wherein the

Assignees

• Ningbo Inlight Tech Co Ltd
• Univ Michigan Regents

Inventors

• Ji Chengang
• Guo Lingjie Jay
• Acharya Saurabh
• Maldonado Stephen

Classifications

• G02B5/288 Primary

  comprising at least one thin film resonant cavity, e.g. in bandpass filters · CPC title

• G02B5/286

  having four or fewer layers, e.g. for achieving a colour effect · CPC title

• G02B5/28 Primary

  Interference filters · CPC title

• G02B5/20

  Filters (polarising elements G02B5/30) · CPC title

• H01L27/3244

  Electricity · mapped topic