US5948176A
Expired / Lapsed
US
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Cadmium-free junction fabrication process for CuInSe2 thin film solar cells
Assignee: Alliance for Sustainable Energy LLC
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Filing: 1997-09-29
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Granted: 1999-09-07
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Expires: 2017-09-29
Abstract
Abstract The present invention provides an economical, simple, dry and controllable semiconductor layer junction forming process to make cadmium free high efficiency photovoltaic cells having a first layer comprised primarily of copper indium diselenide having a thin doped copper indium diselenide n-type region, generated by thermal diffusion with a group II(b) element such as zinc, and a halide, such as chlorine, and a second layer comprised of a conventional zinc oxide bilayer. A photovoltaic device according the present invention includes a first thin film layer of semiconductor material formed primarily from copper indium diselenide. Doping of the copper indium diselenide with zinc chloride is accomplished using either a zinc chloride solution or a solid zinc chloride material. Thermal diffusion of zinc chloride into the copper indium diselenide upper region creates the thin n-type copper indium diselenide surface. A second thin film layer of semiconductor material comprising zinc oxide is then applied in two layers. The first layer comprises a thin layer of high resistivity zinc oxide. The second relatively thick layer of zinc oxide is doped to exhibit low resistivity.
Inventors
- 👤 Kannan V. Ramanathan
- 👤 Miguel A. Contreras
- 👤 Raghu N. Bhattacharya
- 👤 James Keane
- 👤 Rommel Noufi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:53
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F10/16; H10F10/167; H10F77/00; H10F77/10; H10F77/12; H10F77/126; H10F77/1265; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/541; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
110 words
A process for making a thin film heterojunction photovoltaic device comprising the steps of: (a) depositing a first film of p-type copper indium diselenide film on a metal back contact (b) depositing on the upper surface of the copper indium diselenide film a group IIb halide; (c) doping the p-type upper copper indium diselenide film surface n-type by thermal diffusion of the group IIb halide into the copper indium diselenide film surface and cleaning the n-type surface; (d) depositing a second thin film layer of high resistivity zinc oxide; and (e) depositing a third film of n-type transparent zinc oxide on the second thin film high resistivity zinc oxide layer.
Claim 2
Dependent Claim
110 words
A process for making a thin film heterojunction photovoltaic device comprising the steps of: (a) depositing a first film of p-type copper indium diselenide film on a metal back contact (b) depositing on the upper surface of the copper indium diselenide film a group IIb halide; (c) doping the p-type upper copper indium diselenide film surface n-type by thermal diffusion of the group IIb halide into the copper indium diselenide film surface and cleaning the n-type surface; (d) depositing a second thin film layer of high resistivity zinc oxide; and (e) depositing a third film of n-type transparent zinc oxide on the second thin film high resistivity zinc oxide layer.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the group IIb halide is zinc chloride.
Claim 4
Dependent Claim
28 words
A process according to claim 2 wherein zinc chloride is deposited on the copper indium diselenide film surface from solid zinc chloride in a vapor phase through sublimation.
Claim 5
Dependent Claim
27 words
A process according to claim 2 wherein zinc chloride is deposited on the copper indium diselenide film surface from a zinc chloride solution by chemical vapor deposition.
Claim 6
Dependent Claim
16 words
A process according to claim 4 wherein the zinc chloride solution comprises zinc chloride in methanol.
Claim 7
Dependent Claim
21 words
A process according to claim 1 wherein the group IIb halide and copper indium diselenide are thermally diffused at 190-220° C.
Claim 8
Dependent Claim
22 words
A process according to claim 1 wherein the group IIb halide and copper indium diselenide are heated in contact for 10-60 minutes.
Claim 9
Dependent Claim
27 words
A process according to claim 1 wherein cleaning the n-type converted copper indium diselenide film surface comprises rinsing with deionized water and etching with dilute hydrochloric acid.
Claim 10
Dependent Claim
17 words
A process according to claim 8 wherein the hydrochloric acid solution is 10% hydrochloric acid in water.
Claim 11
Dependent Claim
65 words
A thin film photovoltaic device comprising, in order, a first layer of p-type copper indium diselenide semiconductor having a type converted upper region rendered n-type by thermal diffusion of a group IIb halide and, a second layer of high resistivity zinc oxide semiconductor in contact with said first layer, and a third layer of low resistivity zinc oxide semiconductor in contact with said second layer.
Claim 12
Dependent Claim
65 words
A thin film photovoltaic device comprising, in order, a first layer of p-type copper indium diselenide semiconductor having a type converted upper region rendered n-type by thermal diffusion of a group IIb halide and, a second layer of high resistivity zinc oxide semiconductor in contact with said first layer, and a third layer of low resistivity zinc oxide semiconductor in contact with said second layer.
Claim 13
Dependent Claim
14 words
A device according to claim 10, wherein the group IIb halide is zinc chloride.
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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) | 2002-09-06 | 2003-03-08 | 2003-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-06 | 2007-03-08 | 2007-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-06 | 2011-03-08 | 2011-09-07 | $7700.00 | Window Closed / Lapsed |