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US4536260A
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Thin film cadmium selenide electrodeposited from selenosulphite solution
Assignee: GUELPH GUELPH ONTARIO N1G 2W1, University of
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Filing: 1984-05-14
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Granted: 1985-08-20
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Expires: 2004-05-14
Abstract
Abstract A process for electrodepositing a thin layer of cadmium selenide on a suitable substrate is disclosed. The substrate is immersed in an electrolyte bath with pH ranging from 5 to 10 and having an aqueous solution of selenosulphite ions and cadmium ions complexed with nitrilotriacetic acid. The pH range shifts the chemical equilibrium of complexing the cadmium ions towards associated complexed cadmium ions. A voltage is applied to the cathode and anode in the electrolyte to reduce the selenosulphite ions to produce selenide ions at the cathode of a sufficient concentration which reacts with the complexed cadmium ions to electrodeposit thereby cadmium selenide on the cathode. The thin layer of cadmium selenide is particularly useful in a photoelectrochemical cell.
Inventors
- 👤 Michael Cocivera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:42
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/48; C25D5/50; C25D9/00; C25D9/04; C25D9/08; H; H10; H10P; H10P14/00; H10P14/20; H10P14/26; H10P14/265; H10P14/34; H10P14/3402; H10P14/3424; H10P14/3431
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
132 words
In a process for electrodepositing a thin layer of cadmium selenide on a suitable electrically conductive substrate comprising immersing a cathode of said substrate in association with an anode in an electrolyte bath having a pH ranging from 5 to 10 and having an aqueous solution of selenosulphite ions and cadmium ions complexed with a complexing agent where said pH range shifts the chemical equilibrium of complexing said cadmium ions towards associated complexed cadmium ions, applying a voltage across said cathode and anode to reduce said selenosulphite ions to produce selenide ions at said cathode of a sufficient concentration which reacts with the complexed cadmium ions to electrodeposit thereby cadmium selenide on said cathode and annealing said electrodeposited cadmium selenide, the improvement comprising the use of nitrilotriacetic acid as said complexing agent.
Claim 2
Dependent Claim
132 words
In a process for electrodepositing a thin layer of cadmium selenide on a suitable electrically conductive substrate comprising immersing a cathode of said substrate in association with an anode in an electrolyte bath having a pH ranging from 5 to 10 and having an aqueous solution of selenosulphite ions and cadmium ions complexed with a complexing agent where said pH range shifts the chemical equilibrium of complexing said cadmium ions towards associated complexed cadmium ions, applying a voltage across said cathode and anode to reduce said selenosulphite ions to produce selenide ions at said cathode of a sufficient concentration which reacts with the complexed cadmium ions to electrodeposit thereby cadmium selenide on said cathode and annealing said electrodeposited cadmium selenide, the improvement comprising the use of nitrilotriacetic acid as said complexing agent.
Claim 3
Dependent Claim
14 words
A process of claim 1 wherein said electrolyte bath is operated at room temperature.
Claim 4
Dependent Claim
23 words
A process of claim 1 wherein said cadmium selenide is electrodeposited to a thickness of approximately 1 to 2 micrometers on said substrate.
Claim 5
Dependent Claim
19 words
A process of claim 3 wherein said annealing temperatures are in the range of 500° C. to 550° C.
Claim 6
Dependent Claim
31 words
A process of claim 1 wherein said cathode substrate is selected from the group consisting of titanium, cadmium, molybdenum, platinum, indium, tin oxide coated glass, stainless steel, nickel, carbon and gold.
Claim 7
Dependent Claim
17 words
A process of claim 5 wherein said cathodic substrate is titanium and said anode is elemental cadmium.
Claim 8
Dependent Claim
23 words
A process of claim 6 further comprising treating the surface of said titanium cathode to enhance electrodeposition of cadmium selenide onto said cathode.
Claim 9
Dependent Claim
21 words
A process of claim 1 wherein an essentially constant potential of approximately 0.30 volts is applied to said cathode and anode.
Claim 10
Dependent Claim
29 words
A process of claim 1 wherein an essentially constant current density is applied on the cathode which is selected from the range of 0.25 to 1.0 milliamp/cm 2 .
Claim 11
Dependent Claim
24 words
A process of claim 1 wherein said complexed cadmium is stable in an aqueous solution for a period of up to approximately 24 hours.
Claim 12
Dependent Claim
26 words
A process of claim 1 wherein said cadmium selenide is electrodeposited on a cathode substrate having a surface area of at least 1 cm 2 .
Claim 13
Dependent Claim
46 words
A process of claim 1 further comprising preparing a solution containing said selenosulphite ions separately of a solution of said complexed cadmium ions and mixing the two solutions to form said electrolyte bath which is adjusted to a pH in the range of 5 to 10.
Claim 14
Dependent Claim
23 words
A process of claim 12 wherein said solution of selenosulphite is prepared by dissolving elemental selenium in an aqueous solution of a sulphite.
Claim 15
Dependent Claim
28 words
A process of claim 12 or 13 wherein said solution of complexed cadmium ions is prepared by dissolving a cadmium salt in an aqueous solution of a nitriliotriacetate.
Claim 16
Dependent Claim
24 words
A process of claim 1, wherein said pH for said electrolyte bath is weakly basic which is in the range of 7 to 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) | 1988-08-19 | 1989-02-18 | 1989-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-19 | 1993-02-18 | 1993-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-19 | 1997-02-18 | 1997-08-20 | $7700.00 | Window Closed / Lapsed |