US4677250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault tolerant thin-film photovoltaic cell
Assignee: Heritage Power LLC
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Filing: 1985-10-30
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Granted: 1987-06-30
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Expires: 2005-10-30
Abstract
Abstract A thin-film solar cell is made up of semiconductor layers formed on a substrate. The substrate includes an insulator containing electrically conducting nucleation sites which is interposed between the electrical contact of the substrate and the adjacent semiconductor. The insulator can also be optically transparent. Grain boundaries and voids terminate on the insulator. The solar cell is fabricated by selectively introducing nucleation sites into the insulator layer which is formed on the substrate material, and activating the nucleation sites during growth of the semiconductor layers.
Inventors
- 👤 Allen M. Barnett
- 👤 Robert B. Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:34
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F77/00; H10F77/10; H10F77/16; H10F77/169; H10F77/1692; H10F77/20; H10F77/206; H10F77/211; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/541; Y02E10/544
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
91 words
In a thin-film photovoltaic solar cell comprising, in order, a substrate, a first electrical contact, at least one semiconductor layer including at least one photovoltaic junction, and a second electrical contact, the improvement being an insulator containing electrically conductive nucleation sites interposed between the first electrical contact and at least one semiconductor layer, whereby microscopic and macroscopic defects in the semiconductor layer terminate primarily on the insulator rather than on the first electrical contact and the nucleation sites provide for electrical communication between the first electrical contact and the semiconductor layer.
Claim 2
Dependent Claim
91 words
In a thin-film photovoltaic solar cell comprising, in order, a substrate, a first electrical contact, at least one semiconductor layer including at least one photovoltaic junction, and a second electrical contact, the improvement being an insulator containing electrically conductive nucleation sites interposed between the first electrical contact and at least one semiconductor layer, whereby microscopic and macroscopic defects in the semiconductor layer terminate primarily on the insulator rather than on the first electrical contact and the nucleation sites provide for electrical communication between the first electrical contact and the semiconductor layer.
Claim 3
Dependent Claim
16 words
In the solar cell of claim 1 wherein the insulator is a ceramic or glass material.
Claim 4
Dependent Claim
26 words
In the solar cell of claim 1 wherein the insulator is selected from the group consisting of inorganic oxides, carbides, nitrides, borides, silicates, and mixtures thereof.
Claim 5
Dependent Claim
19 words
In the solar cell of claim 3 wherein the insulator is a mixture of aluminum oxide and silicon oxide.
Claim 6
Dependent Claim
13 words
In the solar cell of claim 3 wherein the insulator is aluminum oxide.
Claim 7
Dependent Claim
16 words
In the solar cell of claim 1 wherein the insulator is 0.1 to 100 micrometers thick.
Claim 8
Dependent Claim
23 words
In the solar cell of claim 1 wherein the nucleation site material is selected from the group consisting of metals, semi-metals and semiconductors.
Claim 9
Dependent Claim
13 words
In the solar cell of claim 7 wherein the site material is germanium.
Claim 10
Dependent Claim
13 words
In the solar cell of claim 7 wherein the site material is silicon.
Claim 11
Dependent Claim
23 words
In the solar cell of claim 9 wherein the site material is heavily doped silicon having a resistivity of less than 0.1 ohm-cm.
Claim 12
Dependent Claim
16 words
In the solar cell of claim 10 wherein the site material is silicon doped with aluminum.
Claim 13
Dependent Claim
43 words
In the solar cell of claim 1 wherein at least one semiconductor layer is polycrystalline and the size and distribution of sites within the insulator are selected such that grain size in the semiconductor layer and electrical resistance within the cell are optimum.
Claim 14
Dependent Claim
26 words
In the solar cell of claim 1 wherein the substrate is selected from the group consisting of metals, semi-metals, metallurgical grade semiconductors, ceramics, glass, and polymers.
Claim 15
Dependent Claim
15 words
In the solar cell of claim 13 wherein the substrate is metal in sheet form.
Claim 16
Dependent Claim
14 words
In the solar cell of claim 14 wherein the substrate is a ferrous alloy.
Claim 17
Dependent Claim
12 words
In the solar cell of claim 13 wherein the substrate is glass.
Claim 18
Dependent Claim
31 words
In the solar cell of claim 16 wherein the first electrical contact is a transparent conductor selected from the group consisting of silicon carbide, tin oxide, indium oxide and mixtures thereof.
Claim 19
Dependent Claim
15 words
In the solar cell of claim 17 wherein the first electrical contact is tin oxide.
Claim 20
Dependent Claim
13 words
In the solar cell of claim 1 wherein the insulator is optically transparent.
Claim 21
Dependent Claim
16 words
In the solar cell of claim 19 wherein the first electrical contact is reflective to light.
Claim 22
Dependent Claim
23 words
In the solar cell of claim 19 wherein the thickness of the insulator is selected whereby the insulator serves as a quarter-wave reflector.
Claim 23
Dependent Claim
20 words
In the solar cell of claim 1 wherein the substrate surface is textured to provide for diffuse reflection of light.
Claim 24
Dependent Claim
21 words
In the solar cell of claim 1 wherein the first electrical contact is textured to provide for diffuse reflection of light.
Claim 25
Dependent Claim
27 words
In the solar cell of claim 1 wherein the solar cell is a silicon solar cell comprising oppositely doped regions of silicon semiconductor and a homojunction therebetween.
Claim 26
Dependent Claim
29 words
In the solar cell of claim 1 wherein the solar cell is a gallium arsenide solar cell comprising oppositely doped regions of gallium arsenide semiconductor and a homojunction therebetween.
Claim 27
Dependent Claim
25 words
In the solar cell of claim 1 wherein the semiconductor includes oppositely doped layers of gallium arsenide and gallium aluminum arsenide and a heterojunction therebetween.
Claim 28
Dependent Claim
24 words
In the solar cell of claim 1 wherein the semiconductor includes oppositely doped layers of gallium arsenide and gallium phosphide and a heterojunction therebetween.
Claim 29
Dependent Claim
32 words
In the solar cell of claim 1 wherein the semiconductor includes n-type cadmium sulfide and a p-type semiconductor selected from the group consisting of cadmium telluride, copper indium diselenide, and copper sulfide.
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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) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |