US5466301A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solar cell having an output-increasing, protective cover
Assignee: Spheral Solar Power Inc
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Filing: 1994-06-29
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Granted: 1995-11-14
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Expires: 2014-06-29
Abstract
Abstract A flexible cover (14) for a flexible solar cell (12) protects the cell from the ambient and increases the cell's efficiency. The cell (12)includes silicon particles (16) held in a flexible aluminum sheet matrix (20,22). The cover (14) is a flexible, protective layer (60) of a light-transparent material such as a fluoropolymer, preferably TEFZEL® film having a relatively flat upper, free surface (64) and an opposed surface (66) coated with an adhesive, preferably EVA. The surface (66) is applied to the particles (16) so as to include first portions (68) which conform to the poles (31 P) and the polar regions (31R) of the particles (16) and second, projecting convex (72) or concave (90) prism-like portions which define spaces (78) in conjunction with the reflective surface (20T) of one aluminum sheet (20). Without the cover (14), light (50) falling on the surface (20T) between the particles (16) is wasted, that is, it does not fall on a particle (16). The surfaces of the second portions (72,90) are non-parallel to the direction of the otherwise wasted light (50), which, together with a selected relationship between the refractive indices of the cover 14 and the spaces (78), results in sufficient diffraction of the otherwise wasted light (50) so that about 25% of it is reflected from the surface (20T) onto a particle (16).
Inventors
- 👤 Milfred D. Hammerbacher
- 👤 Russell R. Schmit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:48
CPC Classifications
H; H10; H10F; H10F77/00; H10F77/10; H10F77/14; H10F77/147; H10F19/00; H10F19/80; H10F77/40; H10F77/42; H10F77/484; H10F77/488; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/52
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
230 words
A photovoltaic cell having a cover, the cell including a plurality of spaced semiconductor particles having portions extending away from a reflective surface so that the particle portions are exposed to radiant energy directed at the cell; a substantial amount of the radiant energy which impinges on the reflective surface between adjacent particle portions being wasted due to its being reflected so as to not fall upon the particle portions, the cover comprising: a layer of radiant energy-transparent material having a free surface and an opposed surface on which is a radiation energy-transparent adhesive having a free surface, first portions of the free surface of said adhesive conforming to the polar regions of adjacent particle portions, and second portions of the free surface of said adhesive between the pole-conforming portions thereof extending toward the reflective surface and having surfaces which are non-perpendicular to the direction of the otherwise wasted radiant energy, spaces being defined between the second portions and the reflective surface; both (a) the angular relationship between the surfaces of the second portions and the otherwise wasted radiant energy and (b) the refractive indices of the adhesive and the spaces being such that a significant amount of the otherwise wasted radiant energy which passes through the layer of energy-transparent material, the adhesive and each adhesive-space interface between adjacent particles is reflected by the reflective surface onto the particle portions.
Claim 2
Dependent Claim
230 words
A photovoltaic cell having a cover, the cell including a plurality of spaced semiconductor particles having portions extending away from a reflective surface so that the particle portions are exposed to radiant energy directed at the cell; a substantial amount of the radiant energy which impinges on the reflective surface between adjacent particle portions being wasted due to its being reflected so as to not fall upon the particle portions, the cover comprising: a layer of radiant energy-transparent material having a free surface and an opposed surface on which is a radiation energy-transparent adhesive having a free surface, first portions of the free surface of said adhesive conforming to the polar regions of adjacent particle portions, and second portions of the free surface of said adhesive between the pole-conforming portions thereof extending toward the reflective surface and having surfaces which are non-perpendicular to the direction of the otherwise wasted radiant energy, spaces being defined between the second portions and the reflective surface; both (a) the angular relationship between the surfaces of the second portions and the otherwise wasted radiant energy and (b) the refractive indices of the adhesive and the spaces being such that a significant amount of the otherwise wasted radiant energy which passes through the layer of energy-transparent material, the adhesive and each adhesive-space interface between adjacent particles is reflected by the reflective surface onto the particle portions.
Claim 3
Dependent Claim
13 words
A combination as in claim 1, wherein: the second portions are prism-like projections.
Claim 4
Dependent Claim
12 words
A combination as in claim 2, wherein: the second portions are convexities.
Claim 5
Dependent Claim
12 words
A combination as in claim 2, wherein: the second portions are concavities.
Claim 6
Dependent Claim
67 words
A combination as in claim 2, wherein: the radiant energy is refracted at each projection-space interface and the path taken by the refracted radiant energy is generally along the projection proximate to one of the adjacent particles, onto the reflective surface, and then away from the reflective surface along the projection proximate to another adjacent particle, and then onto the extending portion of such other adjacent particle.
Claim 7
Dependent Claim
55 words
A combination as in claim 2, wherein: the radiant energy is refracted at each projection-space interface and the path taken by the refracted radiant energy is generally along and proximate to one of the adjacent particles, onto the reflective surface, and then away from the reflective surface onto the extending portion of such one particle.
Claim 8
Dependent Claim
45 words
A combination as in claim 2 for a solar cell in which the reflective surface occupies approximately 20% of the cell area, wherein: the cover increases the efficiency of the cell by about 25% for a given amount of radiant energy incident on the cell.
Claim 9
Dependent Claim
26 words
A combination as in claim 1, wherein: the cover optically magnifies the apparent diameters of the particles as viewed from the free surface of the layer.
Claim 10
Dependent Claim
48 words
A combination as in claim 8, wherein: the particles are semiconductor spheres or spheroids having diameters of between about 25 mils to about 45 mils; the reflective surface occupies about 20% of the cell area; the cover is about 41/2 mils thick; and the magnification is about 10%.
Claim 11
Dependent Claim
26 words
A combination as in claim 1, wherein: the reflective surface is a surface of a flexible member which holds the particles; and the cover is flexible.
Claim 12
Dependent Claim
14 words
A combination as in claim 10, wherein: the particles are semiconductor spheres or spheroids.
Claim 13
Dependent Claim
43 words
A combination as in claim 1, wherein: the cell is flexible, and the free surface of the cover and the reflective surface are spaced apart substantially uniformly over the areas of both thereof regardless of the configuration assumed by the cell upon flexing.
Claim 14
Dependent Claim
30 words
A combination as in claim 1, wherein: the free surface of the cover is configured so as to not attract and retain significant amounts of particulate matter from the ambient.
Claim 15
Dependent Claim
16 words
A combination as in claim 13, wherein: the free surface of the cover is substantially smooth.
Claim 16
Dependent Claim
31 words
A combination as in claim 1, wherein: the cover optically magnifies the apparent diameters of the particles as viewed from the free surface of the cover by about at least 10%.
Claim 17
Dependent Claim
11 words
A combination as in claim 1, wherein: the spaces are evacuated.
Claim 18
Dependent Claim
12 words
A combination as in claim 1, wherein: the spaces contain a substance.
Claim 19
Dependent Claim
12 words
A combination as in claim 17, wherein: the substance is a gas.
Claim 20
Dependent Claim
11 words
A combination as in claim 18, wherein: the gas is air.
Claim 21
Dependent Claim
15 words
A combination as in claim 17, wherein: the substance is substantially free of water vapor.
Claim 22
Dependent Claim
12 words
A combination as in claim 17, wherein: the substance is a liquid.
Claim 23
Dependent Claim
12 words
A combination as in claim 17, wherein: the substance is a solid.
Claim 24
Dependent Claim
25 words
A combination as in claim 1, wherein: the material of the layer of energy-transparent material is a fluoropolymer; and the adhesive is ethylene vinyl acetate.
Claim 25
Dependent Claim
12 words
A combination as in claim 23, wherein: the fluoropolymer is TEFZEL® film.
Claim 26
Dependent Claim
29 words
A combination as in claim 24, wherein: the fluoropolymer is about 11/2 mils thick and the adhesive is about 3 mils thick before its free surface is rendered irregular.
Claim 27
Independent Claim
243 words
A method of producing a photovoltaic cell having a cover, the cell including a plurality of spaced semiconductor particles having portions extending away from a reflective surface so that the particle portions are exposed to radiant energy directed at the cell; a substantial amount of the radiant energy which impinges on the reflective surface between adjacent particles being wasted due to its being reflected so as to not fall upon the particle portions, the method comprising: (a) contacting the polar regions of the particles with the free surface of an adhesive residing on a layer of a material, the adhesive and the layer both being radiant energy-transparent; and (b) configuring the free surface of the adhesive to assume an irregular configuration so that (i) first portions thereof conform to the polar regions of adjacent particle portions and second portions thereof between the pole-conforming portions extend toward the reflective surface and have surfaces which are non-perpendicular to the otherwise wasted radiant energy and (ii) spaces are defined between the surfaces of the second portions and the reflective surface; (c) both (i) the angular relationship between the surfaces of the second portions and the otherwise wasted radiant energy and (ii) the refractive indices of the adhesive and the spaces being such that a significant amount of the otherwise wasted radiant energy which passes through the layer, the adhesive and each adhesive-space interface between adjacent particles is reflected by the reflective surface onto the particle portions.
Claim 28
Independent Claim
243 words
A method of producing a photovoltaic cell having a cover, the cell including a plurality of spaced semiconductor particles having portions extending away from a reflective surface so that the particle portions are exposed to radiant energy directed at the cell; a substantial amount of the radiant energy which impinges on the reflective surface between adjacent particles being wasted due to its being reflected so as to not fall upon the particle portions, the method comprising: (a) contacting the polar regions of the particles with the free surface of an adhesive residing on a layer of a material, the adhesive and the layer both being radiant energy-transparent; and (b) configuring the free surface of the adhesive to assume an irregular configuration so that (i) first portions thereof conform to the polar regions of adjacent particle portions and second portions thereof between the pole-conforming portions extend toward the reflective surface and have surfaces which are non-perpendicular to the otherwise wasted radiant energy and (ii) spaces are defined between the surfaces of the second portions and the reflective surface; (c) both (i) the angular relationship between the surfaces of the second portions and the otherwise wasted radiant energy and (ii) the refractive indices of the adhesive and the spaces being such that a significant amount of the otherwise wasted radiant energy which passes through the layer, the adhesive and each adhesive-space interface between adjacent particles is reflected by the reflective surface onto the particle portions.
Claim 29
Dependent Claim
25 words
A method as in claim 26, wherein: the configuring step is effected by the application of heat and/or force to the layer and/or the adhesive.
Claim 30
Dependent Claim
38 words
A method as in claim 26, wherein: the reflective surface is a surface of a flexible member which holds the particles, the cell being flexible and conformal as a consequence, and the cover is similarly flexible and conformal.
Claim 31
Dependent Claim
14 words
A method as in claim 26 wherein: the particles are semiconductor spheres or spheroids.
Claim 32
Dependent Claim
36 words
A method as in claim 26, wherein: the free surface of the layer and the reflective surface are spaced apart substantially uniformly over the areas of both thereof regardless of the configuration assumed by the cell.
Claim 33
Dependent Claim
25 words
A method as in claim 26, wherein: the free surface of the layer is configured so as to not attract and retain ambient particulate matter.
Claim 34
Dependent Claim
16 words
A method as in claim 31, wherein: the free surface of the layer is substantially smooth.
Claim 35
Dependent Claim
40 words
A method as in claim 26, wherein: the reflective surface occupies approximately 20% of the cell area, and the cover increases the efficiency of the cell by about 25% for a given amount of radiant energy incident on the cell.
Claim 36
Dependent Claim
13 words
A method as in claim 26, wherein: the second portions are prism-like projections.
Claim 37
Dependent Claim
12 words
A method as in claim 34, wherein: the second portions are concavities.
Claim 38
Dependent Claim
12 words
A method as in claim 34, wherein: the second portions are convexities.
Claim 39
Dependent Claim
12 words
A method as in claim 26, which further comprises: evacuating the spaces.
Claim 40
Dependent Claim
15 words
A method as in claim 26, which further comprises: filling the spaces with a substance.
Claim 41
Dependent Claim
17 words
A method as in claim 38, wherein: the substance is a gas, a liquid or a solid.
Claim 42
Dependent Claim
11 words
A method as in claim 39, wherein: the substance is air.
Claim 43
Dependent Claim
14 words
A method as in claim 38, wherein: the substance is substantially free of water.
Claim 44
Dependent Claim
19 words
A method as in claim 26, wherein: the layer is a fluoropolymer and the adhesive is ethylene vinyl acetate.
Claim 45
Dependent Claim
12 words
A method as in claim 42, wherein: the fluoropolymer is TEFZEL® film.
Claim 46
Dependent Claim
10 words
A photovoltaic cell made by the method of claim 26.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |