Metal and metal oxide surface texturing

• US 20120017989A1
• Filed: 08/24/2011
• Published: 01/26/2012
• Est. Priority Date: 08/24/2010
• Status: Abandoned Application

• Current Assignee: Clean Cell International, Inc.
• Original Assignee: Clean Cell International, Inc.
• Inventors: Chang, Pai-Chun, Chien, Chung-Jen, Qi, Pengfel
• Application Number:
  US13/216,402
• Publication Number:
  US 20120017989A1
• Time in Patent Office: Days
• US Class Current: 136/259
• CPC Class Codes: C25D 11/04 of aluminium or alloys based thereon
• CPC Class Codes: C25D 11/24 Chemical after-treatment
• CPC Class Codes: C25D 11/26 of refractory metals or alloys based thereon
• CPC Class Codes: H01L 31/02366 of the substrate or of a layer on the substrate, e.g. textured ITO/glass substrate or superstrate, textured polymer layer on glass substrate
• CPC Class Codes: H01L 31/0322 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
• CPC Class Codes: H01L 31/0392 including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate textured substrates H01L31/02366
• CPC Class Codes: H01L 31/03923 including AIBIIICVI compound materials, e.g. CIS, CIGS
• CPC Class Codes: H01L 31/03925 including AIIBVI compound materials, e.g. CdTe, CdS
• CPC Class Codes: H01L 31/056 the light-reflecting means being of the back surface reflector [BSR] type
• CPC Class Codes: H01L 31/0749 including a AIBIIICVI compound, e.g. CdS/CulnSe2 [CIS] heterojunction solar cells
• CPC Class Codes: H01L 31/206 Particular processes or apparatus for continuous treatment of the devices, e.g. roll-to roll processes, multi-chamber deposition
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/541 CuInSe2 material PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method of texturing a metal provides a metal with a thickness of 50 to 400 μm. The metal is anodized, etched and then textured in a first texturing step to produce a first textured surface of the metal. A textured metal is produced with a dimpled surface of dimples with diameters of 5 nm to 2 and a depth of from 2 nm to 2 μm.

Claims

1. A method of texturing a metal, comprising:

providing a metal that has a thickness of 50 to 400 μ

m.

anodizing the metal;

etching the metal;

texturing the metal in a texturing step to produce a metal oxide surface; and

etching the textured metal oxide surface to produce a textured surface of the metal, the textured surface having a dimpled surface of dimples with diameters of 5 nm to 2 μ

m, and a depth of from 2 nm to 2 μ

m

2. The method of claim 1, further comprising:

cleaning the metal; and

polishing the metal prior to anodizing the metal.

3. The method of claim 1, further comprising:

polishing the metal surface prior to anodizing to provide a metal surface with a average roughness no greater than 1 μ

m, wherein roughness is a measurement of height variation compared to a mean value.

4. The method of claim 1, wherein during anodization and oxide is grown on the metal that is removed by etching.

5. The method of claim 1, wherein the etching is done in an acid bath.

6. The method of claim 1, wherein the etching is done at a temperature of 30°

C.-100°

C.

7. The method of claim 6, wherein the etching is done from 20-120 minutes.

8. The method of claim 1, wherein the first texturing is done in a texturing solution bath.

9. The method of claim 8, wherein the solution bath includes acids and surfactants.

10. The method of claim 8, wherein the first texturing step is a second anodization process.

11. The method of claim 1, wherein during the first texturing step, an electric field is provided that induces ion diffusion to form a dimple pattern on the surface of the metal.

12. The method of claim 11, wherein the dimple surface of the textured metal has porous channel-like structures that form the dimpled surface.

13. The method of claim 1, wherein dimple size and texture roughness is controlled by an applied electric field.

14. The method of claim 1, wherein the dimpled surface is a textured metal oxide surface.

15. The method of claim 1, further comprising:

etching the metal oxide in a second etching step to produce a textured surface of the metal

16. The method of claim 1, wherein the metal has a thickness of from 50-400 μ

m.

17. The method of claim 1, wherein the metal has a width of 0.5-2 m.

18. The method of claim 1, wherein the metal has a length of 1-2 m applying a second texturing step.

19. The method of claim 1, further comprising:

mechanically grinding and polished the metal.

20. The method of claim 1, wherein the metal is selected from at least one of, Al, Ti, W, Hf, Ta, Zr and Nb.

21. The method of claim 1, wherein the metal is a foil or a sheet.

22. The method of claim 1, wherein the metal is a pure metal.

23. The method of claim 1, wherein the metal is a compound.

24. The method of claim 1, wherein the metal is a composition that includes non-metals.

25. The method of claim 1, wherein the textured metal is included in a device selected from at least one of, an optical device, reflectors, PV, waveguides electrochemical electrodes, biosensors, chemical sensor, battery and energy storage device.

26. The method of claim 1, wherein the textured metal serves as a bottom substrate or electrode for a variety of devices.

27. A photovoltaic cell, comprising:

a substrate;

a buffer layer;

a contact layer;

an absorber layer;

a window layer;

a transparent conductive oxide (TCO) and

a textured metal layer as a bottom substrate or electrode., wherein the textured metal layer has a dimpled surface of dimples with diameters of 5 nm to 2 μ

m, and a depth of from 2 nm to 2 μ

m.

28. The photovoltaic cell of claim 27, wherein the absorber layer is p or n type.

29. The photovoltaic cell of claim 27, wherein the window layer is p or n type.

30. The method of claim 27, wherein the dimple surface of the textured metal has porous channel-like structures that form the dimpled surface.

31. The method of claim 27, wherein dimple size and texture roughness is controlled by an applied electric field.

32. The method of claim 27, wherein the dimpled surface is a textured metal oxide surface.

33. The method of claim 27, wherein the metal has a thickness of from 50-400 μ

m.

34. The method of claim 27, wherein the metal has a width of 0.5-2 m.

35. The method of claim 27, wherein the metal has a length of 1-2 m

36. The method of claim 27, wherein the metal is selected from at least one of, Al, Ti, W, Hf, Ta, Zr and Nb.

37. The method of claim 27, wherein the metal is a foil or a sheet.

38. The method of claim 27, wherein the metal is a pure metal.

39. The method of claim 27, wherein the metal is a compound.

40. The method of claim 27, wherein the metal is a composition that includes non-metals.