1. A solar cell comprising a contact made from a mixture wherein, prior to firing, the mixture comprises:
a. a solids portion and
b. an organics portion,
c. wherein the solids portion comprises
i. from about 85 to about 99 wt % of a conductive metal component, and
ii. from about 1 to about 15 wt % of a glass component, wherein the glass component is lead-free.
2. The solar cell contact of claim 1 wherein the contact is a front contact, wherein the metal component comprises silver, and wherein the glass component comprises from about 5 to about 85 mol % Bi2O3, and from about 1 to about 70 mol % SiO2.
3. The solar cell contact of claim 2 wherein the glass component further comprises about 0.1 to about 30 mol % V2O5.
4. The solar cell contact of claim 2 wherein the glass component further comprises about 1 to about 20 mol % of a trivalent oxide of an element selected from the group consisting of Al, B, La, Y, Ga, In, Ce, and Cr.
5. The solar cell contact of claim 2 wherein the glass component further comprises about 0.1 to about 15 mol % of a tetravalent oxide of an element selected from the group consisting of Ti, Zr and Hf.
6. The solar cell contact of claim 2 wherein the glass component further comprises about 0.1 to about 20 mol % of a pentavalent oxide of an element selected from the group consisting of P, Ta, Nb, and Sb.
7. The solar cell contact of claim 2 wherein the glass component further comprises about 0.1 to about 25 mol % of an alkali oxide.
8. The solar cell contact of claim 2 wherein the glass component further comprises about 0.1 to about 20 mol % of an alkaline earth oxide.
9. The solar cell contact of claim 2 wherein the glass component further comprises about 0.1 to about 25 mol % of ZnO.
10. The solar cell contact of claim 2 wherein the glass component further comprises about 0.1 to about 12 mol % Ag2O.
11. The solar cell contact of claim 2 wherein the solids portion further comprises a crystalline additive selected from the group consisting of Bi2O3, Sb2O3, In2O3, Ga2O3, SnO, ZnO, SiO2, ZrO2, Al2O3, B2O3, V2O5, Ta2O5, 12Bi2O3.SiO2, 2Bi2O3.SiO2, 3Bi2O3.5SiO2, Bi2O3.4SiO2, 6Bi2O3.SiO2, Bi2O3.SiO2, 2Bi2O3.3SiO2, Bi2O3.2TiO2, 2Bi2O3.3TiO2, 2Bi2O3.4TiO2, and 6Bi2O3.TiO2, 6Bi2O3.V2O5, BiVO4, 2Bi2O3.3V2O5, BiV3O9, 6.5Bi2O3.2.5V2O5.TiO2, 2ZnO.3TiO2, ZnO.SiO2, ZrO2.SiO2, MgO.V2O5, SrO.V2O5, CaO.V2O5, BaO.V2O5, ZnO.V2O5, Na2O.17V2O5, K2O.4V2O5, 2Li2O.5V2O5and reaction products thereof and combinations thereof.
12. The solar cell contact of claim 2 wherein the solids portion further comprises about 0.5 to about 25 wt % of a metal selected from the group consisting of Pb, Bi, Zn, In, Ga, Sb and alloys thereof.
13. The solar cell contact of claim 2 wherein the silver component comprises silver selected from the group consisting of present as flakes, powder, or colloidal particles of silver, wherein the solids portion further comprises phosphorus, at least a portion of which is present as a coating on at least portion of the silver flakes, powder or colloidal particles.
14. The solar cell of claim 1 further comprising a silver rear contact made from a mixture wherein, prior to firing, the mixture comprises:
a. a solids portion and
b. an organics portion,
c. wherein the solids portion comprises
i. from about 85 to about 99 wt % of a conductive metal component, and
ii. from about 1 to about 15 wt % of a glass component, wherein the glass component is lead-free.
15. The solar cell contact of claim 1 wherein the contact is a back contact, wherein the metal component comprises aluminum, and wherein the glass component comprises from about 5 to about 65 mol % Bi2O3 and from about 15 to about 70 mol % SiO2.
16. The solar cell contact of claim 15 further comprising from about 0.1 to about 35 mol % B2O3.
17. The solar cell contact of claim 15 wherein the glass component further comprises about 0.1 to about 25 mol % of at least one alkali oxide.
18. The solar cell contact of claim 15 wherein the glass component further comprises about 0.1 to about 25 mol % ZnO.
19. The solar cell contact of claim 15 wherein the glass component further comprises about 0.1 to about 10 mol % TiO2.
20. A solar panel comprising the solar cell of claim 1.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. An optical device comprising reflecting means for at least partially reflecting light, the reflecting means comprising at least one optical surface comprising a multilayer optical film comprising:
(a) a first layer comprising an oriented birefringent polymer, the first layer having an average thickness of not more than about 0.5 microns; and
(b) a second layer of a selected polymer, each second layer having an average thickness of not more than 0.5 microns.
2. A device according to claim 1, wherein the first layer comprises a crystalline naphthalene dicarboxylic acid polyester.
3. A device according to claim 1, wherein the oriented birefringent first layer is more birefringent than the second polymer.
4. A device according to claim 1, further comprising a plurality of first and second layers, wherein one of the second layers is located between each adjacent pair of first layers.
5. A device according to claim 4, wherein the first and second layers are adhered to each other.
6. A device according to claim 1, wherein the film comprises at least fifty of each of the first and second layers.
7. A device according to claim 1, wherein the film has been stretched along a first in-plane axis.
8. A device according to claim 7, wherein the film has a second dimension along a second in-plane axis generally orthogonal to the first in-plane axis, and further wherein the amount of stretch along the first in-plane axis is at least twice the second dimension.
9. A device according to claim 8, wherein the first layers of an oriented birefringent polymer have a higher index of refraction associated with at least one in-plane axis than the index of refraction of the second layers of said second polymer.
10. A device according to claim 9, wherein said higher index of refraction is at least 0.05 higher.
11. A device according to claim 9, wherein said higher index of refraction is at least 0.10 higher.
12. A device according to claim 9, wherein said higher index of refraction is at least 0.20 higher.
13. A device according to claim 1, wherein the film has been stretched in at least two in-plane directions.
14. A device according to claim 2, wherein the naphthalene dicarboxylic acid polyester is a poly(ethylene naphthalate).
15. A device according to claim 2, wherein the naphthalene dicarboxylic acid polyester is a copolyester comprising naphthalate units and terephthalate units.
16. A device according to claim 2, wherein said second polymer is a polyester.
17. A device according to claim 16, wherein said second polymer comprises naphthalene units.
18. A device according to claim 16, wherein said second polymer is a copolyester comprising naphthalate units and terephthalate units.
19. A device according to claim 2, wherein said second polymer is a polystyrene.
20. A device according to claim 2, wherein said second polymer is a fluoropolymer.
21. A device according to claim 2, wherein said second polymer is a polyacrylate, polymethacrylate, polymethylmethacrylate, or polyolefin.
22. A device according to claim 2, wherein said film has an average reflectivity, for at least one plane of polarization, of at least 50% over at least a 100 nm wide band.
23. An optical device comprising a body having a cross-section which defines at least two opposing optical surfaces, at least a portion of at least one of the optical surfaces comprising a multilayer optical film, the film comprising:
(a) a first layer comprising an oriented birefringent, the first layer having an average thickness of not more than about 0.5 microns; and
(b) a second layer of a selected polymer, each second layer having an average thickness of not more than 0.5 microns.
24. A device according to claim 23, wherein the first layer comprises a crystalline naphthalene dicarboxylic acid polyester.
25. An optical device according to claim 23, wherein substantially all of the optical surfaces comprise the multilayer optical film.
26. An optical device according to claim 23, wherein the multilayer optical film is partially reflective.
27. An optical device according to claim 26, wherein the partially reflective multilayer optical film comprises a reflective polarizer.
28. An optical device according to claim 26, wherein the partially reflective multilayer optical film comprises at least one void formed in the multilayer optical film.
29. An optical device according to claim 23, wherein the first and second optical surfaces lie substantially in planes which are arranged substantially parallel to each other.
30. An optical device according to claim 23, wherein the body comprises a diverging wedge optical device.
31. An optical device according to claim 23, wherein the body comprises a converging wedge optical device.
32. An optical device according to claim 23, wherein the body comprises a light pipe.
33. An optical device according to claim 23, wherein the body defines a substantially enclosed volume and further wherein the optical device comprises at least one light source located within the volume.
34. An optical device according to claim 33, wherein substantially all of the interior surfaces of the volume comprise the multilayer optical film.
35. An optical device comprising a body having a cross-section which defines at least two opposing optical surfaces, at least a portion of each of the optical surfaces comprising a multilayer optical film, the film comprising:
(a) a plurality of first layers each comprising a crystalline naphthalene dicarboxylic acid polyester having a positive stress optical coefficient, each of the plurality of first layers having an average thickness of not more than about 0.5 microns; and
(b) a second layer of a selected second polymer located between adjacent pairs of the first layers, each second layer having an average thickness of not more than 0.5 microns, wherein the naphthalene dicarboxylic acid polyester in the first layers is more positively birefringent than the second polymer in the second layers.