US4602120A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solar cell manufacture
Assignee: Atlantic Richfield Co
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Filing: 1983-11-25
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Granted: 1986-07-22
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Expires: 2003-11-25
Abstract
Abstract An improved solar cell, and method for manufacture, in which a back side reverse p-n junction is formed prior to metallization and a gridded back side metallization material, chosen so that it penetrates the p-n junction where it is present, is fired into the wafer. The finished solar cell has improved efficiency despite the presence of the reverse p-n junction over a majority of the back face surface.
Inventors
- 👤 G. Felix Wakefield
- 👤 Hyouk I. Yoo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:38
CPC Classifications
H; H10; H10F; H10F71/00; H10F71/121; H10F10/00; H10F10/10; H10F10/14; H10F77/00; H10F77/20; H10F77/206; H10F77/211; H10F77/215; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
101 words
In a method for manufacturing solar cells wherein an active impurity of an opposite conductivity imparting type is introduced into both major faces of a semiconductor wafer to establish p-n junctions, and back contacts are formed by metallization using a material chosen so that it penetrates any p-n junction to form a low resistance ohmic contact through any such junction, the improvement comprising: applying said material in a gridded pattern covering no more than 50% of the back face of said wafer, whereby at least 50% of said p-n junction on said back face remains after formation of said ohmic contact.
Claim 2
Dependent Claim
101 words
In a method for manufacturing solar cells wherein an active impurity of an opposite conductivity imparting type is introduced into both major faces of a semiconductor wafer to establish p-n junctions, and back contacts are formed by metallization using a material chosen so that it penetrates any p-n junction to form a low resistance ohmic contact through any such junction, the improvement comprising: applying said material in a gridded pattern covering no more than 50% of the back face of said wafer, whereby at least 50% of said p-n junction on said back face remains after formation of said ohmic contact.
Claim 3
Dependent Claim
115 words
A solar cell having an improved back face contact formed by the process of: (a) introducing an active impurity of an opposite conductivity imparting type into the back face of a semiconductor wafer to establish a p-n junction therein; (b) applying a metallization material in a gridded pattern covering no more than 50% of the back face, said material being chosen so that upon firing it penetrates said p-n junction; and (c) firing said wafer with said material to cause said metallization to penetrate said p-n junction and form a low resistance ohmic contact to the bulk of said wafer, whereby at least 50% of said back face p-n junction remains in the finished device.
Claim 4
Dependent Claim
115 words
A solar cell having an improved back face contact formed by the process of: (a) introducing an active impurity of an opposite conductivity imparting type into the back face of a semiconductor wafer to establish a p-n junction therein; (b) applying a metallization material in a gridded pattern covering no more than 50% of the back face, said material being chosen so that upon firing it penetrates said p-n junction; and (c) firing said wafer with said material to cause said metallization to penetrate said p-n junction and form a low resistance ohmic contact to the bulk of said wafer, whereby at least 50% of said back face p-n junction remains in the finished device.
Claim 5
Dependent Claim
32 words
A solar cell according to claim 2 wherein during step (a) the same active impurity is introduced into the front face of said semiconductor wafer to establish an active p-n junction therein.
Claim 6
Dependent Claim
40 words
A solar cell according to claim 2 wherein, prior to step (c), metallization material is applied to the front face of said wafer and said front face metallization is fired during step (c) to form a front face ohmic contact.
Claim 7
Dependent Claim
98 words
A solar cell comprising: a semiconductor wafer having a light receiving face and a back face, an active p-n junction formed on the light receiving face, first conductor means on and in electrical contact with said light receiving face, a reverse p-n junction formed on the back face of said wafer, second conductor means on the back face of said wafer and alloyed through said reverse p-n junction and in ohmic contact with the bulk of said wafer, said second conductor means in the form of a grid pattern covering less than fifty percent of said back face.
Claim 8
Dependent Claim
98 words
A solar cell comprising: a semiconductor wafer having a light receiving face and a back face, an active p-n junction formed on the light receiving face, first conductor means on and in electrical contact with said light receiving face, a reverse p-n junction formed on the back face of said wafer, second conductor means on the back face of said wafer and alloyed through said reverse p-n junction and in ohmic contact with the bulk of said wafer, said second conductor means in the form of a grid pattern covering less than fifty percent of said back face.
Claim 9
Dependent Claim
22 words
A solar cell according to claim 5 wherein said second conductor means covers from five to twenty percent of said back face.
Claim 10
Dependent Claim
14 words
A solar cell according to claim 5 wherein said second conductor means includes aluminum.
Claim 11
Dependent Claim
19 words
A solar cell according to claim 7 wherein said second conductor means includes about two percent by weight aluminum.
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) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |