US4508932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon-based solar energy conversion cells
Assignee: University of Toronto Innovations Foundation
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Filing: 1984-06-21
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Granted: 1985-04-02
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Expires: 2004-06-21
Abstract
Abstract Silicon-based solar cells devised hitherto have used crystalline silicon because of its acceptable electrical characteristics. Amorphous silicon is much cheaper and has better optical absorption characteristics, but its electrical characteristics are so poor that it cannot be used, without some additional treatment such as hydrogenation. The invention provides a method of production of solar cells using amorphous silicon in which the silicon is evaporated in a suitable vacuum onto a substrate in the presence of a positive field which opposes the migration of the positive silicon ions toward the substrate. The resulting devices are found to have much improved electrical characteristics while retaining a good absorption characteristic. A tentative hypothesis is given for the unexpected improvement.
Inventors
- 👤 Stefan Zukotynski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:22
CPC Classifications
H; H10; H10F; H10F71/00; H10F71/10; H10F71/103; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
148 words
A method of making an amorphous silicon-based solar energy conversion device comprising: placing a substrate to be coated and a source of silicon vapour in an enclosure and establishing a vacuum of a least 1×10 -4 Torr in the enclosure, heating the silicon source in the said vacuum to a temperature such as to cause the production of heated silicon vapour within the enclosure, whereby the substrate is exposed in the enclosure under said vacuum to the heated silicon vapour for deposit thereon of a layer of amorphous silicon, applying an electric field between the source and the substrate with the substrate positive with respect to the source, so that the electric field opposes the deposition of positive silicon ions on the substrate to result in a layer of amorphous silicon having improved electrical characteristics as compared to a layer desposited in the absence of an electric field.
Claim 2
Independent Claim
148 words
A method of making an amorphous silicon-based solar energy conversion device comprising: placing a substrate to be coated and a source of silicon vapour in an enclosure and establishing a vacuum of a least 1×10 -4 Torr in the enclosure, heating the silicon source in the said vacuum to a temperature such as to cause the production of heated silicon vapour within the enclosure, whereby the substrate is exposed in the enclosure under said vacuum to the heated silicon vapour for deposit thereon of a layer of amorphous silicon, applying an electric field between the source and the substrate with the substrate positive with respect to the source, so that the electric field opposes the deposition of positive silicon ions on the substrate to result in a layer of amorphous silicon having improved electrical characteristics as compared to a layer desposited in the absence of an electric field.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1, wherein the said vacuum is at least 1×10 -6 Torr
Claim 4
Dependent Claim
24 words
A method as claimed in claim 1, wherein the electric field has a value of from about 10 to about 33 volts per cm.
Claim 5
Dependent Claim
24 words
A method as claimed in claim 2, wherein the electric field has a value of from about 10 to about 33 volts per cm.
Claim 6
Dependent Claim
37 words
A method as claimed in claim 1, wherein the potential difference of the field has a value of from about 200 to about 500 volts, applied over a distance of about 15 cm to about 20 cm.
Claim 7
Dependent Claim
37 words
A method as claimed in claim 2, wherein the potential difference of the field has a value of from about 200 to about 500 volts, applied over a distance of about 15 cm to about 20 cm.
Claim 8
Dependent Claim
21 words
A method as claimed in claim 1, wherein the substrate is heated to a temperature not higher than about 350° C.
Claim 9
Dependent Claim
21 words
A method as claimed in claim 2, wherein the substrate is heated to a temperature not higher than about 350° C.
Claim 10
Dependent Claim
19 words
A method as claimed in claim 1, wherein the substrate is heated to a temperature of about 200° C.
Claim 11
Dependent Claim
19 words
A method as claimed in claim 2, wherein the substrate is heated to a temperature of about 200° C.
Claim 12
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 1.
Claim 13
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 2.
Claim 14
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 3.
Claim 15
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 4.
Claim 16
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 5.
Claim 17
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 6.
Claim 18
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 7.
Claim 19
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 8.
Claim 20
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 9.
Claim 21
Dependent Claim
14 words
A silicon-based solar energy conversion device when prepared by the method of claim 10.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-01 | 1988-10-01 | 1989-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-01 | 1992-10-01 | 1993-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-01 | 1996-10-01 | 1997-04-02 | $7700.00 | Window Closed / Lapsed |