US4133698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tandem junction solar cell
Assignee: Texas Instruments Inc
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Filing: 1977-12-27
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Granted: 1979-01-09
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Expires: 1997-12-27
Abstract
Abstract A solar cell having first and second closely spaced, parallel P-N junctions is fabricated, wherein the illuminated surface is totally free of metallization, i.e., the junction nearest the illuminated surface is not electrically connected, and thereby participates only indirectly in the collection of photo-generated carriers by providing a charge field to suppress the front surface recombination and to enhance collection at the back side junction. All metallization is on the back side, which preferably includes an interposed finger pattern of N+ and P+ zones.
Inventors
- 👤 Shang-Yi Chiang
- 👤 Bernard G. Carbajal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:54
CPC Classifications
H; H10; H10F; H10F77/00; H10F77/30; H10F77/306; H10F77/311; H10F77/315; H10F10/00; H10F10/10; H10F10/14; H10F10/146; H10F77/20; H10F77/206; H10F77/211; H10F77/219; H10F77/70; H10F77/703; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
158 words
A solar cell comprising: a. a semiconductor body predominantly of one conductivity type having substantially parallel opposite surfaces, b. a first PN junction in said body, formed by a first region of opposite conductivity type extending along a major part of one of said surfaces, said one surface being substantially free of metallization, or other shadowing effect, thereby being adapted to receive incident radiation, c. a second PN junction in said body, substantially parallel to said first junction, formed by second region of opposite conductivity type adjacent the opposite surface of said body, said junctions being electrically separate from each other, and spaced apart by a distance of no more than 150 micrometers, and d. ohmic contacts to said second region and to a central portion of said body, respectively, on said opposite surface whereby said first junction is electrically floating and provides a charge field to supress front surface recombination and enhances collection at said second junction.
Claim 2
Dependent Claim
158 words
A solar cell comprising: a. a semiconductor body predominantly of one conductivity type having substantially parallel opposite surfaces, b. a first PN junction in said body, formed by a first region of opposite conductivity type extending along a major part of one of said surfaces, said one surface being substantially free of metallization, or other shadowing effect, thereby being adapted to receive incident radiation, c. a second PN junction in said body, substantially parallel to said first junction, formed by second region of opposite conductivity type adjacent the opposite surface of said body, said junctions being electrically separate from each other, and spaced apart by a distance of no more than 150 micrometers, and d. ohmic contacts to said second region and to a central portion of said body, respectively, on said opposite surface whereby said first junction is electrically floating and provides a charge field to supress front surface recombination and enhances collection at said second junction.
Claim 3
Dependent Claim
21 words
A cell as in claim 1 wherein said body is a monocrystalline silicon wafer having a thickness of about 50 μm.
Claim 4
Dependent Claim
30 words
A cell as in claim 1 wherein said one conductivity type is P-type, and the central region of said cell has a resistivity of about 0.1 ohm-cm to 10 ohm-cm's.
Claim 5
Dependent Claim
19 words
A cell as in claim 1 wherein the depth of said first junction is about 0.01 to 0.3 μm.
Claim 6
Dependent Claim
30 words
A cell as in claim 1 wherein said second region of opposite conductivity type is of fingered geometry, interdigitated with fingered contact regions to the central region of said body.
Claim 7
Dependent Claim
22 words
A cell as in claim 1 wherein said body is a polycrystalline ribbon or sheet having a thickness of about 50 μm.
Claim 8
Dependent Claim
20 words
A cell as in claim 1 wherein said body is a semiconductor selected from IIIA-VA compounds and from IIB-VIA compounds.
References Cited (Backward Citations)
US4072541A
Cited
US4070206A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-08 | 1982-07-10 | 1983-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-08 | 1986-07-10 | 1987-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-08 | 1990-07-10 | 1991-01-09 | $7700.00 | Window Closed / Lapsed |