Polishing coated substrates

Patent metadata

Field	Value
Publication number	US-9406822-B2
Application number	US-201113261646-A
Country	US
Kind code	B2
Filing date	Oct 27, 2011
Priority date	Oct 27, 2010
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A process for the production of an optoelectronic device, such as a photovoltaic cell or a light emitting diode is disclosed. The process comprises providing a substrate having a conductive coating on at least one surface, the conductive coating having an initial roughness and at least one or more spikes, and applying a functional component to the coated surface of the substrate. The surface of the substrate having the conductive coating has been subjected to a polishing step using at least one brush to reduce the height of the spikes inherent to the conductive coating and to give the conductive coating a final roughness. By reducing the spikes there is less potential for the optoelectronic device to suffer from electrical shunts which reduce the efficiency of the device.

First claim

The invention claimed is:

1. A process of producing an optoelectronic device, the process comprising the steps of:
a) providing a glass substrate;
b) applying on at least one surface of the glass substrate a transparent conductive oxide, the transparent conductive oxide forming a coating having an exposed surface with an initial roughness and at least one or more spikes inherent to the exposed surface of the transparent conductive oxide coating;
c) polishing the exposed surface of the transparent conductive oxide coating using at least one brush to reduce the height of the at least one or more spikes inherent to the exposed surface of the transparent conductive oxide coating to produce a polished transparent conductive oxide coating with a final roughness;
d) following step c), applying a functional component to the polished surface of the transparent conductive oxide coating.

2. The process as claimed in claim 1 , wherein the initial roughness and the final roughness are substantially the same.

3. The process as claimed in claim 1 , wherein the final roughness is less than the initial roughness by between 5% and 40%.

4. The process as claimed in claim 1 , wherein the final roughness is 40% lower than the initial roughness.

5. The process as claimed in claim 4 , wherein the final roughness is 30%-40% lower than the initial roughness.

6. The process as claimed in claim 5 , wherein the final roughness is 20%-30% lower than the initial roughness.

7. The process as claimed in claim 6 , wherein the final roughness is 10%-20% lower than the initial roughness.

8. The process as claimed in claim 7 , wherein the final roughness is 5%-10% lower than the initial roughness.

9. The process as claimed in claim 1 , wherein the optoelectronic device comprises a photovoltaic cell.

10. The process as claimed in claim 1 , wherein the functional component is a component of a photovoltaic device.

11. The process as claimed in claim 1 , wherein the optoelectronic device is a light emitting diode device.

12. The process as claimed in claim 1 , wherein the functional component comprises a material for use in light emitting diodes.

13. The process as claimed in claim 1 , wherein the polishing step uses a liquid polishing medium.

14. The process as claimed in claim 13 , wherein the liquid polishing medium is an aqueous polishing medium.

15. The process as claimed in claim 13 , wherein the liquid polishing medium further comprises an abrasive.

16. The process as claimed in claim 15 , wherein the abrasive comprises a metal oxide abrasive.

17. The process as claimed in claim 1 , wherein the polishing step uses a rotary brush.

18. The process as claimed in claim 17 , wherein the rotary brush, during polishing, has an axis of rotation transverse to the surface of the substrate.

19. The process according to claim 18 , wherein the rotary brush has a rotational speed relative to the substrate of less than 1000 rpm.

20. The process according to claim 19 , wherein the rotational speed relative to the substrate is between 50 and 500 rpm.

21. The process according to claim 20 , wherein the rotational speed relative to the substrate is between 100 and 300 rpm.

22. The process as claimed in claim 17 , wherein the bristles of the brush comprise a synthetic material.

23. The process as claimed in claim 22 , wherein the bristles of the brush are nylon or polyester.

24. The process as claimed in claim 22 , wherein the diameter of the bristles of the brush are in the range 0.1 to 1.0 mm.

25. The process as claimed in claim 22 , wherein the length of the bristles of the brush are in the range 5 to 50 mm.

26. The process as claimed in claim 22 , wherein one or more of the bristles of the brush comprise an abrasive material.

27. The process as claimed in claim 1 , wherein the conductive coating on the substrate is a conductive metal oxide.

28. The process as claimed in claim 27 , wherein the conductive metal oxide comprises tin oxide.

29. The process as claimed in claim 28 , wherein the tin oxide is fluorine doped tin oxide.

30. The process as claimed in claim 1 , wherein the conductive coating on the substrate is deposited by a chemical vapour deposition step.

31. A process of removing spikes from a layer of transparent conductive oxide in the production of an optoelectronic device, the process comprising the steps of:
a) providing a glass substrate;
b) applying on at least one surface of the glass substrate a transparent conductive oxide coating, the transparent conductive oxide forming a coating having an exposed surface with an initial roughness and at least one or more spikes inherent to the exposed surface of the transparent conductive oxide coating;
c) polishing the exposed surface of the transparent conductive oxide coating using at least one brush to reduce the height of the at least one or more spikes inherent to the exposed surface of the conductive coating to give the transparent conductive coating a final roughness;
d) after step c) applying a functional component to the transparent conductive oxide coating on the surface of the substrate.

32. The process as claimed in claim 31 , wherein the conductive coating on the substrate is a conductive metal oxide.

33. The process as claimed in claim 31 , wherein the conductive metal oxide comprises tin oxide.

34. The process as claimed in claim 31 , wherein the tin oxide is fluorine doped tin oxide.

35. The process as claimed in claim 31 , wherein the conductive coating on the substrate is deposited by a chemical vapour deposition step.

Assignees

• Bamber David Lawrence
• Warren Paul David
• Manning Troy Darrell
• Mcsporran Neil
• Holmes Paul Arthur
• Pilkington Group Ltd

Inventors

• Bamber David Lawrence
• Warren Paul David
• Manning Troy Darrell
• Mcsporran Neil
• Holmes Paul Arthur

Classifications

• H10P70/27

  during, before or after processing of conductive materials, e.g. polysilicon or amorphous silicon layers · CPC title

• H10H20/82

  Roughened surfaces, e.g. at the interface between epitaxial layers · CPC title

• H10F77/1694

  the films including Group I-III-VI materials, e.g. CIS or CIGS · CPC title

• H10F77/169 Primary

  Thin semiconductor films on metallic or insulating substrates · CPC title

• H10F71/138

  Manufacture of transparent electrodes, e.g. transparent conductive oxides [TCO] or indium tin oxide [ITO] electrodes · CPC title