US3947717A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoconductor of cadmium selenide and aluminum oxide
Assignee: RCA Corp
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Filing: 1975-03-31
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Granted: 1976-03-30
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Expires: 1995-03-31
Abstract
Abstract A low dark current photoconductive body includes an aluminum oxide overlayer on a cadmium selenide base layer. A transition region is provided at the interface region between the base layer and the overlayer and consists of a graded transition of cadmium and selenium with increasing amounts of aluminum and oxygen. An alternative body is disclosed omitting the overlayer. A blocking contact is provided within a portion of the body including the overlayer and/or the transition region.
Inventors
- 👤 Charles John Busanovich
- 👤 John Theodore Fischer
- 👤 Robert Milton Moore
- 👤 John A. VAN Raalte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:57
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/39; H01J29/45; H01J29/451; H01J29/456; H01J9/00; H01J9/20; H01J9/233; H10; H10F; H10F99/00
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
123 words
A photoconductive device comprising: a. a photoconductive body including in a direction of thickness: 1. a first material region substantially of n type electrical conductivity cadmium selenide; 2. a second material region substantially of aluminum oxide; 3. a transition region along an interfacing region between said first and second material regions consisting of a graded atomic transition of the material compositions of said first and second material regions; b. a blocking contact within a portion of said photoconductive body including said transition and second material regions; c. contacting means for applying an electrical potential across opposed major surfaces of said body whereby charged carriers may be conducted through said body in said direction of thickness in accordance with light impinging on said body.
Claim 2
Dependent Claim
123 words
A photoconductive device comprising: a. a photoconductive body including in a direction of thickness: 1. a first material region substantially of n type electrical conductivity cadmium selenide; 2. a second material region substantially of aluminum oxide; 3. a transition region along an interfacing region between said first and second material regions consisting of a graded atomic transition of the material compositions of said first and second material regions; b. a blocking contact within a portion of said photoconductive body including said transition and second material regions; c. contacting means for applying an electrical potential across opposed major surfaces of said body whereby charged carriers may be conducted through said body in said direction of thickness in accordance with light impinging on said body.
Claim 3
Dependent Claim
64 words
A photoconductive device in accordance with claim 1, wherein said transition region consists of a material having a graded atomic composition, progressing in a direction of thickness from said first to said second material regions, initially of substantially equal amounts of cadmium and selenium substantially as CdSe, to an atomic composition substantially of aluminum and oxygen in the ratio of approximately 2 to 3.
Claim 4
Dependent Claim
18 words
The photoconductive device of claim 2, wherein said cadmium selenide is substantially polycrystalline and includes multiple crystallographic phases.
Claim 5
Dependent Claim
24 words
The photoconductive device of claim 3, wherein the combined thickness of said second material region and transition region is less than about 5,000 Angstroms.
Claim 6
Dependent Claim
36 words
The photoconductive device of claim 4, wherein said body additionally includes a third material region on said second material region consisting of a high resistance chalcogenide compound having a resistivity of greater than 10 8 ohm-cm.
Claim 7
Dependent Claim
44 words
The photoconductive device of claim 5, wherein said high resistance compound consists of a material selected from the group consisting of zinc sulfide, arsenic disulfide, arsenic trisulfide, arsenic triselenide, thallium sulfide, thallium selenide, zinc selenide, cadmium telluride, antimony trisulfide, antimony triselenide, and mixtures thereof.
Claim 8
Dependent Claim
30 words
The photoconductive device of claim 1, wherein said contacting means includes an electrically conductive film on one of said major opposed surfaces of said body on said first material region.
Claim 9
Dependent Claim
11 words
The photoconductive device of claim 7, wherein said film is transparent.
Claim 10
Dependent Claim
42 words
A photoconductive imaging device in accordance with claim 8, wherein said first material region is approximately 1 to 2 microns in thickness, and wherein the combined thickness of said transition and second material regions is from approximately 100 to approximately 500 Angstroms.
Claim 11
Dependent Claim
147 words
A camera tube comprising: a. an evacuated envelope with a transparent portion, b. an electron beam forming and scanning means for scanning an electron beam along a path within the envelope; and c. a target mounted within the envelope in the path of the electron beam and including a major surface for receiving a light image transmitted through said transparent portion; the target including: 1. a photoconductive body including in a direction of thickness: i. a first material region substantially of n type electrical conductivity cadmium selenide; ii. a second material region substantially of aluminum oxide; iii. a transition region along an interfacing region between said first and second material regions consisting of a graded atomic transition of the material composition of said first and second material regions; and 2. a blocking contact within a portion of said photoconductive body including said transition and second material regions.
Claim 12
Dependent Claim
147 words
A camera tube comprising: a. an evacuated envelope with a transparent portion, b. an electron beam forming and scanning means for scanning an electron beam along a path within the envelope; and c. a target mounted within the envelope in the path of the electron beam and including a major surface for receiving a light image transmitted through said transparent portion; the target including: 1. a photoconductive body including in a direction of thickness: i. a first material region substantially of n type electrical conductivity cadmium selenide; ii. a second material region substantially of aluminum oxide; iii. a transition region along an interfacing region between said first and second material regions consisting of a graded atomic transition of the material composition of said first and second material regions; and 2. a blocking contact within a portion of said photoconductive body including said transition and second material regions.
Claim 13
Dependent Claim
78 words
A camera tube in accordance with claim 10, wherein said transition material region is substantially of contrasting electrical conductivity to that associated with said first material region; said transition material region having a graded atomic composition, progressing in a direction of thickness from said first to said second material region, consisting initially of substantially equal amounts of cadmium and selenium to an atomic composition consisting substantially of aluminum and oxygen in the ratio of approximately 2 to 3.
Claim 14
Dependent Claim
25 words
A camera tube in accordance with claim 11, wherein the combined thickness of said transition and second material regions is less than about 5,000 Angstroms.
Claim 15
Dependent Claim
40 words
A camera tube in accordance with claim 12, wherein said first material region is approximately 1 to 2 microns in thickness, and wherein the combined thickness of said transition and second material regions is from approximately 100 to 500 Angstroms.
Claim 16
Dependent Claim
20 words
A camera tube in accordance with claim 11, wherein said cadmium selenide is substantially polycrystalline and includes multiple crystallographic phases.
Claim 17
Dependent Claim
38 words
A camera tube in accordance with claim 14, additionally comprising a third material region consisting of an overlayer on said second material region of a high resistance chalcogenide compound having a resistivity of greater than 10 8 ohm-cm.
Claim 18
Dependent Claim
46 words
A camera tube in accordance with claim 15, wherein said high resistance compound consists of a material selected from the group consisting of zinc sulfide, arsenic disulfide, arsenic trisulfide, arsenic triselenide, thallium sulfide, thallium selenide, zinc selenide, cadmium telluride, antimony trisulfide, antimony triselenide, and mixtures thereof.
Claim 19
Dependent Claim
45 words
A camera tube in accordance with claim 16, wherein a portion of the surface of said transparent portion within the interior of said envelope includes a transparent electrically conductive film having a major surface in electrical contact with said first material region of said target.
Claim 20
Dependent Claim
16 words
A camera tube in accordance with claim 17, wherein said film consists essentially of tin oxide.
Claim 21
Dependent Claim
115 words
A photoconductive device comprising: a. a photoconductive body including in a direction of thickness: 1. a region substantially of n type electrical conductivity cadmium selenide, and 2. a transition region abutting said cadmium selenide region substantially of a graded atomic composition, progressing in a direction of thickness away from said cadmium selenide region, of initially cadmium selenide to a composition of cadmium and selenium with increasing amounts of aluminum and oxygen, said transition region including a blocking contact; b. contacting means for applying an electrical potential across opposed major surfaces of said body whereby charged carriers may be conducted through said body in said direction of thickness in accordance with light impinging on said body.
Claim 22
Dependent Claim
115 words
A photoconductive device comprising: a. a photoconductive body including in a direction of thickness: 1. a region substantially of n type electrical conductivity cadmium selenide, and 2. a transition region abutting said cadmium selenide region substantially of a graded atomic composition, progressing in a direction of thickness away from said cadmium selenide region, of initially cadmium selenide to a composition of cadmium and selenium with increasing amounts of aluminum and oxygen, said transition region including a blocking contact; b. contacting means for applying an electrical potential across opposed major surfaces of said body whereby charged carriers may be conducted through said body in said direction of thickness in accordance with light impinging on said body.
Claim 23
Dependent Claim
18 words
The photoconductive device of claim 19, wherein said cadmium selenide is substantially polycrystalline and includes multiple crystallographic phases.
Claim 24
Dependent Claim
33 words
The photoconductive device of claim 20, wherein said body additionally includes along said transition region a region consisting of a high resistance chalcogenide compound having a resistivity of greater than 10 8 ohm-cm.
Claim 25
Dependent Claim
44 words
The photoconductive device of claim 21, wherein said high resistance compound consists of a material selected from the group consisting of zinc sulfide, arsenic disulfide, arsenic trisulfide, arsenic triselenide, thallium sulfide, thallium selenide, zinc selenide, cadmium telluride, antimony trisulfide, antimony triselenide, and mixtures thereof.
Claim 26
Dependent Claim
30 words
The photoconductive device of claim 22, wherein said contacting means includes an electrically conductive film on one of said major opposed surfaces of said body on said first material region.
Claim 27
Dependent Claim
11 words
The photoconductive device of claim 23, wherein said film is transparent.
Claim 28
Dependent Claim
137 words
A camera tube comprising: a. an evacuated envelope with a transparent portion, b. an electron beam forming and scanning means for scanning an electron beam along a path within the envelope; and c. a target mounted within the envelope in the path of the electron beam and including a major surface for receiving a light image transmitted through said transparent portion; the target including: 1. a photoconductive body including in a direction of thickness; i. a region substantially of n type electrical conductivity cadmium selenide; ii. a transition region abutting said cadmium selenide region substantially of a graded atomic composition, progressing in a direction of thickness away from said cadmium selenide region, of initially cadmium selenide to a composition of cadmium and selenium with increasing amounts of aluminum and oxygen, said transition region including a blocking contact.
Claim 29
Dependent Claim
137 words
A camera tube comprising: a. an evacuated envelope with a transparent portion, b. an electron beam forming and scanning means for scanning an electron beam along a path within the envelope; and c. a target mounted within the envelope in the path of the electron beam and including a major surface for receiving a light image transmitted through said transparent portion; the target including: 1. a photoconductive body including in a direction of thickness; i. a region substantially of n type electrical conductivity cadmium selenide; ii. a transition region abutting said cadmium selenide region substantially of a graded atomic composition, progressing in a direction of thickness away from said cadmium selenide region, of initially cadmium selenide to a composition of cadmium and selenium with increasing amounts of aluminum and oxygen, said transition region including a blocking contact.
Claim 30
Dependent Claim
27 words
A camera tube in accordance with claim 25, wherein said transition material region is substantially of contrasting electrical conductivity to that associated with said first material region.
Claim 31
Dependent Claim
20 words
A camera tube in accordance with claim 26, wherein said cadmium selenide is substantially polycrystalline and includes multiple crystallographic phases.
Claim 32
Dependent Claim
32 words
A camera tube in accordance with claim 27, additionally comprising an overlayer on said second material region of a high resistance chalcogenide compound having a resistivity of greater than 10 8 ohm-cm.
Claim 33
Dependent Claim
46 words
A camera tube in accordance with claim 28, wherein said high resistance compound consists of a material selected from the group consisting of zinc sulfide, arsenic disulfide, arsenic trisulfide, arsenic triselenide, thallium sulfide, thallium selenide, zinc selenide, cadmium telluride, antimony trisulfide, antimony triselenide, and mixtures thereof.
Claim 34
Dependent Claim
37 words
A camera tube in accordance with claim 29, wherein an inner surface of said transparent portion includes a transparent electrically conductive film having a major surface in electrical contact with said cadmium selenide region of said target.
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) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |