Photovoltaic module cleaner
The present invention relates to methods for cleaning semiconductors used in photovoltaic cells and modules, and methods for manufacturing p-n junctions for photovoltaic cells and modules. More particularly, the method comprises providing at least one semiconductor layer of a photovoltaic module and scrubbing the surface of the least one semiconductor layer in the presence of a chemical solution.
1. A method for preparing a semiconductor for a photovoltaic module, comprising:
providing a semiconductor layer over a photovoltaic module substrate;
applying a chemical solution to a surface of the semiconductor layer;
scrubbing the surface of the semiconductor layer with a scrubber in the presence of the chemical solution; and
providing a back contact adjacent to the scrubbed surface of the semiconductor layer.
2. The method of claim 1 , wherein the scrubbing duration is about 0.1 minutes to about 60 minutes.
3. The method of claim 2 , wherein the scrubbing duration is about 0.5 minutes to about 10 minutes.
4. The method of claim 1 , wherein the pressure between the scrubber and the surface of the semiconductor layer is about 0.5 kPa to about 150 kPa.
5. The method of claim 4 , wherein the pressure between the scrubber and the surface of the semiconductor layer is about 3 kPa to about 35 kPa.
6. The method of claim 1 , wherein the chemical solution comprises detergent.
7. The method of claim 1 , wherein the chemical solution comprises soap.
8. The method of claim 1 , wherein the chemical solution comprises distilled water.
9. The method of claim 1 , wherein the chemical solution is applied to the surface of the semiconductor layer by immersing the semiconductor layer in the chemical solution.
10. The method of claim 1 , wherein the chemical solution is applied to the surface of the semiconductor layer through the scrubber.
11. The method of claim 1 , wherein the chemical solution is applied to the surface of the semiconductor layer through a spray nozzle.
12. The method of claim 1 , wherein the chemical solution is applied to the surface of the semiconductor layer at a flow rate of about 1 liter/minute to about 100 liters/minute.
13. The method of claim 12 , wherein the chemical solution is applied to the surface of the semiconductor layer at a flow rate of about 5 liters/minute to about 20 liters/minute.
14. The method of claim 1 , wherein the semiconductor layer comprises cadmium telluride.
15. The method of claim 1 , wherein the semiconductor layer comprises copper indium gallium selenide.
16. A method of manufacturing a p-n junction for a photovoltaic module, the method comprising:
providing a first semiconductor layer over a photovoltaic module substrate;
scrubbing a surface of the first semiconductor layer with a scrubber in the presence of a chemical solution;
providing a second semiconductor layer over the scrubbed surface of the first semiconductor layer to form a p-n junction;
scrubbing a surface of the second semiconductor layer with a scrubber in the presence of the chemical solution; and
placing a back contact over the scrubbed surface of the second semiconductor layer.
17. The method of claim 16 , wherein scrubbing the surface of the first semiconductor layer has a duration of about 0.1 minute to about 60 minutes, and wherein scrubbing the surface of the second semiconductor layer has a duration or about 0.1 minute to about 60 minutes.
18. The method of claim 17 , wherein scrubbing the surface of the first semiconductor layer has a duration of about 0.5 minutes to about 10 minutes, and wherein scrubbing the surface of the second semiconductor layer has a duration of about 0.5 minutes to about 10 minutes.
19. The method of claim 16 , wherein the pressure between the scrubber and the surface of the first semiconductor layer during scrubbing is about 0.5 kPa to about 150 kPa, and wherein the pressure between the scrubber and the surface of the second semiconductor layer during scrubbing is about 0.5 kPa to about 150 kPa.
20. The method of claim 19 , wherein the pressure between the scrubber and the surface of the first semiconductor layer during scrubbing is about 3 kPa to about 35 kPa, and wherein the pressure between the scrubber and the surface of the second semiconductor layer during scrubbing is about 3 kPa to about 35 kPa.
21. The method claim 16 , wherein the chemical solution is applied to the surface of the first semiconductor layer by immersing the first semiconductor layer in the chemical solution, and wherein the chemical solution is applied to the surface of the second semiconductor layer by immersing the second semiconductor layer in the chemical solution.
22. The method of claim 16 , wherein the chemical solution is applied to the surface of the first semiconductor layer through the scrubber, and wherein the chemical solution is applied to the surface of the second semiconductor layer through the scrubber.
23. The method of claim 16 , wherein the chemical solution is applied to the surface of the first semiconductor layer through a spray nozzle, and wherein the chemical solution is applied to the surface of the second semiconductor layer through the spray nozzle.
24. The method of claim 16 , wherein the chemical solution is applied to the surface of the first semiconductor layer at a flow rate of about 0.1 liter/minute to about 100 liters/minute, and wherein the chemical solution is applied to the surface of the second semiconductor layer at a flow rate of about 0.1 liter/minute to about 100 liters/minute.
25. The method of claim 24 , wherein the chemical solution is applied to the surface of the first semiconductor layer at a flow rate of about 5 liters/minute to about 20 liters/minute, and wherein the chemical solution is applied to the surface of the second semiconductor layer at a flow rate of about 5 liters/minute to about 20 liters/minute.