PHOTOLUMINESCENT BACKING SHEET FOR PHOTOVOLTAIC MODULES

• US 20090211631A1
• Filed: 12/30/2008
• Published: 08/27/2009
• Est. Priority Date: 01/03/2008
• Status: Abandoned Application

• Current Assignee: Madico Incorporated (Lintec Corporation)
• Original Assignee: Madico Incorporated (Lintec Corporation)
• Inventors: Temchenko, Marina, Avison, David William, Mannarino, Frank Anthony, Lim, Samuel
• Application Number:
  US12/345,954
• Publication Number:
  US 20090211631A1
• Time in Patent Office: Days
• US Class Current: 136/256
• CPC Class Codes: H01L 31/049 Protective back sheets
• CPC Class Codes: H01L 31/055 where light is absorbed and re-emitted at a different wavelength by the optical element directly associated or integrated with the PV cell, e.g. by using luminescent material, fluorescent concentrators or up-conversion arrangements
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

The present invention provides a protective backing sheet for photovoltaic modules. The backing sheets are capable of absorbing a wide range of solar wavelengths (UV, IR and visible) and re-emitting the absorbed solar radiation as a photons wherein the energy is at or greater than the band gap energy of corresponding semiconductor. The backing sheet can be used in a variety of applications including in photovoltaic devices.

Claims

1. A backing sheet for a photovoltaic module comprising:

a polymer layer comprising one or more white pigments and one or more photo luminescent materials.

2. The backing sheet of claim 1 wherein the polymer layer comprises about 20 to 60 weight percent of white pigments.

3. The backing sheet of claim 1 wherein the white pigment comprise one or more of titanium dioxide, calcium carbonate, lithopone, and zinc sulfate.

4. The backing sheet of claim 1 further comprising a first outer layer of weatherable film.

5. The backing sheet of claim 4 further comprising one or more layers chosen from the group of a polyester, EVA, polycarbonate, polyolefin, polyurethane, liquid crystal polymer, aclar, aluminum, sputtered aluminum oxide polyester, sputtered silicon dioxide polyester, sputtered aluminum oxide polycarbonate, and sputtered silicon dioxide polycarbonate, sputtered aluminum oxide fluorocopolymer with crosslinkable functional groups, sputtered silicon oxide fluorocopolymer with crosslinkable functional groups.

6. The backing sheet of claim 1 wherein the photo luminescent materials absorb UV light and re-emit it as a visible light.

7. The backing sheet of claim 6 wherein the photoluminescent material is an optical brightener.

8. The backing sheet of claim 1 wherein the polymer layer comprises an organic solvent soluble and/or water dispersible, crosslinkable amorphous fluoropolymers.

9. The backing sheet of claim 8 where the fluoropolymer is a fluorocopolymer of chlorotrifluoroethylene (CTFE) and one or more alkyl vinyl ethers

10. The backing sheet of claim 1 wherein the polymer layer further comprises a light reflecting coating on the outer surface thereof.

11. The backing sheet of claim 5 wherein one or more of the additional layers comprise one or more white pigments and one or more photo luminescent materials.

12. A photovoltaic module comprising:

a backing sheet comprising one or more white pigments and one or more photo luminescent material, wherein the backing sheet is capable of absorbing solar radiation and converting the absorbed solar radiation into a peak emission wavelength; and

one or more semiconductors comprised of a material with a band gap at or near the peak emission wavelength.

13. The photovoltaic module of claim 12 wherein the backing sheet comprises a polymer layer comprising about 20 to 60 weight percent of white pigments.

14. The photovoltaic module of claim 13 wherein the white pigment comprise one or more of titanium dioxide, calcium carbonate, lithopone, and zinc sulfate.

15. The photovoltaic module of claim 12 wherein the backing sheet further comprises a first outer layer of weatherable film.

16. The photovoltaic module of claim 12 wherein the backing sheet further comprises one or more layers chosen from the group of a polyester, EVA, polycarbonate, polyolefin, polyurethane, liquid crystal polymer, aclar, aluminum, sputtered aluminum oxide polyester, sputtered silicon dioxide polyester, sputtered aluminum oxide polycarbonate, sputtered silicon dioxide polycarbonate, sputtered aluminum oxide fluorocopolymer with crosslinkable functional groups, sputtered silicon oxide fluorocopolymer with crosslinkable functional groups.

17. The photovoltaic module of claim 12 wherein the photo luminescent materials absorb UV light and re-emit it as a visible light.

18. The photovoltaic module of claim 12 wherein the photoluminescent material is an optical brightener.

19. The photovoltaic module of claim 13 wherein the polymer layer comprises an organic solvent soluble and/or water dispersible, crosslinkable amorphous fluoropolymers.

20. The photovoltaic module of claim 19 where the fluoropolymer is a fluorocopolymer of chlorotrifluoroethylene (CTFE) and one or more alkyl vinyl ethers

21. The photovoltaic module of claim 13 wherein the polymer layer further comprises a light reflecting coating on the outer surface thereof.

22. The photovoltaic module of claim 16 wherein one or more of the additional layers comprise one or more white pigments and one or more photo luminescent materials.

23. A method of boosting the power of a photovoltaic module with a backing sheet comprising:

applying a coating comprising one or more white pigments and one or more photo luminescent materials to a portion of the backing sheet facing the photovoltaic cells.