US4772564A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault tolerant thin-film photovoltaic cell fabrication process
Assignee: Heritage Power LLC
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Filing: 1987-05-13
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Granted: 1988-09-20
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Expires: 2007-05-13
Abstract
Abstract A thin-film solar cell on a substrate 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. The 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.
Inventors
- 👤 Allen M. Barnett
- 👤 Robert B. Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:29
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F77/00; H10F77/10; H10F77/16; H10F77/162; H10F77/164; H10F77/169; H10F77/1692; H10F77/20; H10F77/206; H10F77/211; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y10; Y10S; Y10S148/00; Y10S148/056; Y10S148/122
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
89 words
A process for fabricating a thin-film photovoltaic solar cell comprising the steps of: a. providing a substrate with an electrically conductive surface; b. preparing a selected electrically insulative material with selected nucleation site material dispersed therein; c. applying the insulative material over the electrically conductive surface of the substrate; d. activating the site material to form electrically conductive nucleation sites in said electrically insulative material; e. forming at least one semiconductor layer over the insulative material having activated sites; and f. applying electrical contact means to the solar cell.
Claim 2
Dependent Claim
89 words
A process for fabricating a thin-film photovoltaic solar cell comprising the steps of: a. providing a substrate with an electrically conductive surface; b. preparing a selected electrically insulative material with selected nucleation site material dispersed therein; c. applying the insulative material over the electrically conductive surface of the substrate; d. activating the site material to form electrically conductive nucleation sites in said electrically insulative material; e. forming at least one semiconductor layer over the insulative material having activated sites; and f. applying electrical contact means to the solar cell.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the substrate is selected from metal sheets, metal foils, polymer films, ceramics, and glass.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein the substrate is a ferrous alloy.
Claim 5
Dependent Claim
10 words
The process of claim 2 wherein the substrate is glass.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein the electrically conductive surface is a metal film.
Claim 7
Dependent Claim
26 words
The process of claim 1 wherein the electrically conductive surface is a transparent conductive coating selected from silicon carbide, tin oxide, indium oxide, and mixtures thereof.
Claim 8
Dependent Claim
20 words
The process of claim 1 wherein the substrate is glass and the electrically conductive surface is coating of tin oxide.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the insulative material is an inorganic oxide, nitride, carbide, boride, or mixture thereof.
Claim 10
Dependent Claim
12 words
The process of claim 8 wherein the insulative material is aluminum oxide.
Claim 11
Dependent Claim
20 words
The process of claim 1 wherein the nucleation site material comprises silicon, germanium, a silicon compound, or a germanium compound.
Claim 12
Dependent Claim
13 words
The process of claim 10 wherein the nucleation site material is silicon dioxide.
Claim 13
Dependent Claim
37 words
The process of claim 1 wherein the step of preparing the electrically insulative material containing nucleation site material includes mixing solid particles of insulative material and nucleation site material with a liquid vehicle to form a paste.
Claim 14
Dependent Claim
16 words
The process of claim 12 wherein the step of applying the insulative material is screen printing.
Claim 15
Dependent Claim
25 words
The process of claim 13 wherein the step of applying the insulative material is followed by drying and firing to form a dense adherent coating.
Claim 16
Dependent Claim
20 words
The process of claim 1 wherein the step of forming at least one semiconductor layer is the solution growth process.
Claim 17
Dependent Claim
25 words
The process of claim 15 wherein the step of activating the nucleation site material occurs during the step of forming at least one semiconductor layer.
Claim 18
Dependent Claim
28 words
The process of claim 16 wherein the step of activating the nucleation site material is provided by adding a selected chemical reducing agent to the solution growth solvent.
Claim 19
Dependent Claim
14 words
The process of claim 17 wherein the at least one semiconductor layer is silicon.
Claim 20
Dependent Claim
29 words
The process of claim 18 wherein the solution growth solvent is selected from tin, gallium, bismuth, indium, lead, germanium, and alloys thereof and the selected reducing agent is aluminum.
Claim 21
Dependent Claim
57 words
The process of claim 19 wherein the substrate is a steel sheet, the step of preparing the insulative material with dispersed nucleation site material is mixing solid particles of aluminum oxide and silicon dioxide with amyl acetate to form a paste, and the step of applying the insulative material is screen printing followed by drying and firing.
Claim 22
Dependent Claim
26 words
The process of claim 1 wherein the at least one semiconductor layer is a compound semiconductor selected from groups III and V of the Periodic Table.
Claim 23
Dependent Claim
35 words
The process of claim 21 wherein the steps of activating the nucleation site material and forming at least one semiconductor layer are provided by solution growth from molten gallium containing aluminum as a reducing agent.
Claim 24
Dependent Claim
20 words
The process of claim 1 wherein the at least one semiconductor layer is two oppositely doped layers of gallium arsenide.
Claim 25
Dependent Claim
28 words
The process of claim 1 wherein the step of providing an electrically conductive surface includes texturing the surface of the substrate to provide for diffuse reflection of light.
Claim 26
Dependent Claim
29 words
The process of claim 1 wherein the step of applying the insulative material includes applying the insulative material to a preselected thickness which provides for enhanced reflection of light.
Claim 27
Dependent Claim
14 words
The process of claim 25 wherein the preselected thickness satisfies the quarter-wave reflector condition.
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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) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |