US4774194A
Expired / Lapsed
US
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Process for manufacturing a solar cell device
Assignee: Mitsubishi Electric Corp
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Filing: 1987-12-31
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Granted: 1988-09-27
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Expires: 2007-12-31
Abstract
Abstract A process for manufacturing a solar cell device, including the steps of (1) forming, on a semiconductor substrate, a removable layer having a crystal lattice structure identical or similar to that of the substrate; (2) forming, on the removable layer, a solar cell structure having a crystal lattice structure identical or similar to that of the removable layer; (3) forming, on the solar cell structure, a reinforcement layer having a sufficient mechanical strength to support solar cell structure, the removal layer being formed of a material whose rate of etching is higher than that of the solar cell structure and the reinforcement layer; (4) and removing the removable layer by etching, to separate the solar cell structure supported by the reinforcement layer from the substrate, so that the surface of the solar cell structure for receiving incident light is exposed.
Inventors
- 👤 Shigeru Hokuyou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:03
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F10/14; H10F10/144; H10F71/00; H10F71/127; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/544; Y02E10/547; Y02P; Y02P70/00; Y02P70/50; Y10; Y10S; Y10S117/00; Y10S117/915; Y10S148/00; Y10S148/135; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
314 words
A process for manufacturing a solar cell device, comprising the steps of: providing a semiconductor substrate; forming, on said substrate, a removable layer having a crystal lattice structure identical or similar to that of said structure; forming, on said removable layer, a solar cell structure having a crystal lattice structure identical or similar to that of said removable layer; forming, on said solar cell structure, a reinforcement layer having a sufficient mechanical strength to support said solar cell structure, said removal layer being formed of a material whose rate of etching is higher than that of said solar cell structure and that of said reinforcement layer; and selectively removing said removable layer by etching, to separate said solar cell structure supported by said reinforcement layer from said substrate, so that a surface of said solar cell structure for receiving incident light is exposed; wherein said step of forming said solar cell structure comprises forming, on said removable layer, a first solar cell layer having a crystal lattice structure identical or similar to that of said removable layer, and having a first conductivity type, forming, on said first solar cell layer, a second solar cell layer having a crystal lattice structure identical or similar to that of said first solar cell layer and having said first conductivity type, said first and said second solar cell layers forming a heterojunction therebetween, and forming, on said second solar cell layer, a third solar cell layer having a crystal lattice structure identical to said second solar cell layer and having a second conductivity type; wherein said substrate is a single crystal substrate formed of GaAs or AlGaAs, said removable layer is formed of Al x1 Ga 1-x1 As, where x1≧0.9, said first solar cell layer is formed of Al x2 Ga 1-x2 As, where 0.4≦x2≦0.8, and said second and said third solar cell layer are formed of GaAs.
Claim 2
Dependent Claim
314 words
A process for manufacturing a solar cell device, comprising the steps of: providing a semiconductor substrate; forming, on said substrate, a removable layer having a crystal lattice structure identical or similar to that of said structure; forming, on said removable layer, a solar cell structure having a crystal lattice structure identical or similar to that of said removable layer; forming, on said solar cell structure, a reinforcement layer having a sufficient mechanical strength to support said solar cell structure, said removal layer being formed of a material whose rate of etching is higher than that of said solar cell structure and that of said reinforcement layer; and selectively removing said removable layer by etching, to separate said solar cell structure supported by said reinforcement layer from said substrate, so that a surface of said solar cell structure for receiving incident light is exposed; wherein said step of forming said solar cell structure comprises forming, on said removable layer, a first solar cell layer having a crystal lattice structure identical or similar to that of said removable layer, and having a first conductivity type, forming, on said first solar cell layer, a second solar cell layer having a crystal lattice structure identical or similar to that of said first solar cell layer and having said first conductivity type, said first and said second solar cell layers forming a heterojunction therebetween, and forming, on said second solar cell layer, a third solar cell layer having a crystal lattice structure identical to said second solar cell layer and having a second conductivity type; wherein said substrate is a single crystal substrate formed of GaAs or AlGaAs, said removable layer is formed of Al x1 Ga 1-x1 As, where x1≧0.9, said first solar cell layer is formed of Al x2 Ga 1-x2 As, where 0.4≦x2≦0.8, and said second and said third solar cell layer are formed of GaAs.
Claim 3
Dependent Claim
33 words
A process according to claim 1, wherein the first solar cell layer has a relatively small light absorption, and the second and the third solar cell layers have a relatively large light absorption.
Claim 4
Dependent Claim
68 words
A process according to claim 1, wherein the removable layer is formed to a thickness of about 10 to 20 micrometers, the first solar cell layer is formed to a thickness of about 0.05 to 0.1 micrometers, the second solar cell layer is formed to a thickness of about 0.5 micrometers, and the third solar cell layer is formed to a thickness of about 5 to 10 micrometers.
Claim 5
Dependent Claim
23 words
A process according to claim 1, wherein the removable layer is formed by liquid phase epitaxy or metal organic chemical vapor deposition (MOCVD).
Claim 6
Dependent Claim
19 words
A process according to claim 1, wherein the reinforcement layer is formed of amorphous silicon of a low resistivity.
Claim 7
Dependent Claim
21 words
A process according to claim 5, wherein the reinforcement layer is formed to a thickness of about 50 to 100 micrometers.
Claim 8
Dependent Claim
17 words
A process according to claim 5, wherein the reinforcement layer is formed by plasma chemical vapor deposition.
Claim 9
Dependent Claim
29 words
A process according to claim 1, wherein the step of removing the removable layer comprises etching the removable layer using an etching solution of an acid or an alkali.
Claim 10
Dependent Claim
28 words
A process according to claim 1, further comprising the step of forming, on the exposed surface of the solar cell structure, a grid electrode and an antireflection film.
Claim 11
Dependent Claim
23 words
A process according to claim 1, further comprising the step of dividing the solar cell structure supported by the reinforcement layer into chips.
Claim 12
Dependent Claim
25 words
The process of claim 1, wherein said removable layer is formed to a thickness which is in the range of 10 to 20 microns inclusive.
Claim 13
Dependent Claim
13 words
The process of claim 1, wherein said second solar cell layer is p-type.
Claim 14
Dependent Claim
12 words
The process of claim 1, wherein said etching steps uses aqueous HF.
Claim 15
Dependent Claim
25 words
The process of claim 1, wherein said reinforcement layer is formed to a thickness which is in the range of 50 to 100 microns inclusive.
Claim 16
Dependent Claim
12 words
The process of claim 1, wherein said reinforcement layer has low resistivity.
Claim 17
Dependent Claim
11 words
The process of claim 1, wherein said reinforcement layer comprises silicon.
Claim 18
Dependent Claim
11 words
The process of claim 1, wherein said reinforcement layer is amorphous.
Claim 19
Dependent Claim
151 words
A process for manufacturing a solar cell device, comprising the steps of: (a) providing a substrate; (b) epitaxially forming, on said substrate, a removable layer consisting essentially of Al x1 Ga 1-x1 As, where x1≧0.9; (c) forming, on said removable layer, a first solar cell layer consisting essentially of Al x2 Ga 1-x2 As, where 0.4≦x2≦0.8; (d) forming, on said first solar cell layer, a second solar cell layer consisting essentially of GaAs; (e) forming, on said second solar cell layer, a third solar cell layer consisting essentially of GaAs, said second and third solar cell layers having opposite conductivity types; (f) forming, on said third solar cell layer, a reinforcement layer; and (g) selectively etching away said removable layer, to separate said first, second, and third solar cell layers, supported by said reinforcement layer, from said substrate, so that said first solar cell layer is exposed for receiving incident light.
Claim 20
Dependent Claim
151 words
A process for manufacturing a solar cell device, comprising the steps of: (a) providing a substrate; (b) epitaxially forming, on said substrate, a removable layer consisting essentially of Al x1 Ga 1-x1 As, where x1≧0.9; (c) forming, on said removable layer, a first solar cell layer consisting essentially of Al x2 Ga 1-x2 As, where 0.4≦x2≦0.8; (d) forming, on said first solar cell layer, a second solar cell layer consisting essentially of GaAs; (e) forming, on said second solar cell layer, a third solar cell layer consisting essentially of GaAs, said second and third solar cell layers having opposite conductivity types; (f) forming, on said third solar cell layer, a reinforcement layer; and (g) selectively etching away said removable layer, to separate said first, second, and third solar cell layers, supported by said reinforcement layer, from said substrate, so that said first solar cell layer is exposed for receiving incident light.
Claim 21
Dependent Claim
25 words
The process of claim 18, wherein said removable layer is formed to a thickness which is in the range of 10 to 20 microns inclusive.
Claim 22
Dependent Claim
12 words
The process of claim 18, wherein said substrate consists essentially of GaAs.
Claim 23
Dependent Claim
13 words
The process of claim 18, wherein said second solar cell layer is p-type.
Claim 24
Dependent Claim
13 words
The process of claim 18, wherein said selective etching step uses aqueous HF.
Claim 25
Dependent Claim
22 words
The process of claim 18, wherein said substrate used in step (a) is used repeatedly for repeating said steps (b) through (g).
Claim 26
Dependent Claim
25 words
The process of claim 18, wherein said reinforcement layer is formed to a thickness which is in the range of 50 to 100 microns inclusive.
Claim 27
Dependent Claim
12 words
The process of claim 18, wherein said reinforcement layer has low resistivity.
Claim 28
Dependent Claim
11 words
The process of claim 18, wherein said reinforcement layer comprises silicon.
Claim 29
Dependent Claim
11 words
The process of claim 18, wherein said reinforcement layer is amorphous.
Claim 30
Dependent Claim
32 words
The process of claim 18, further comprising the step, subsequent to said step (g), of forming, on the exposed surface of first solar cell layer, a grid electrode and an antireflection film.
Claim 31
Dependent Claim
141 words
A process for manufacturing a solar cell device, comprising the steps of: (a) providing a substrate; (b) epitaxially forming, on said substrate, a removable layer consisting essentially of Al x1 Ga 1-x1 As, where x1 has a value between 0.9 and 0.1 inclusive; (c) epitaxially forming, on said removable layer, a first solar cell layer consisting essentially of Al x2 Ga 1-x2 As, where x2 has a value between 0.4 and 0.8 inclusive; (d) epitaxially forming, on said first solar cell layer, a second solar cell layer and a third solar cell layer, said second and third layers having opposite conductivity types; (e) depositing a reinforcement layer on said third solar cell layer; and (f) selectively etching away said removable layer, to separate said first, second, third, and reinforcement layers from said substrate; and (g) repeating said steps (b) through (f).
Claim 32
Dependent Claim
141 words
A process for manufacturing a solar cell device, comprising the steps of: (a) providing a substrate; (b) epitaxially forming, on said substrate, a removable layer consisting essentially of Al x1 Ga 1-x1 As, where x1 has a value between 0.9 and 0.1 inclusive; (c) epitaxially forming, on said removable layer, a first solar cell layer consisting essentially of Al x2 Ga 1-x2 As, where x2 has a value between 0.4 and 0.8 inclusive; (d) epitaxially forming, on said first solar cell layer, a second solar cell layer and a third solar cell layer, said second and third layers having opposite conductivity types; (e) depositing a reinforcement layer on said third solar cell layer; and (f) selectively etching away said removable layer, to separate said first, second, third, and reinforcement layers from said substrate; and (g) repeating said steps (b) through (f).
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) | 1991-09-27 | 1992-03-28 | 1992-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-27 | 1996-03-28 | 1996-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-27 | 2000-03-28 | 2000-09-27 | $7700.00 | Window Closed / Lapsed |