US3699401A
Expired / Lapsed
US
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Photoemissive electron tube comprising a thin film transmissive semiconductor photocathode structure
Assignee: RCA Corp
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Filing: 1971-05-11
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Granted: 1972-10-17
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Expires: 1991-05-11
Abstract
Abstract A transmissive semiconductor photocathode structure comprising a first monocrystalline epitaxial layer of silicon or germanium about 200 to 300 nanometers thick on a major surface of a transparent monocrystalline dielectric substrate. On the silicon or germanium layer is a second monocrystalline epitaxial layer of a III-V or II-VI semiconductor compound having a thickness of at least about three microns. On the second layer is a third monocrystalline epitaxial layer of a III-V semiconductor compound having an energy bandgap smaller than the second layer compound and having a thickness on the order of from about one micron to about five microns. Also disclosed is a photoemissive electron tube utilizing the transmissive photocathode structure, with a work function reducing material deposited on the emissive surface of the third layer.
Inventors
- 👤 James Joseph Tietjfn
- 👤 Brown F Williams
- 👤 Chin Chun Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:29
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J1/00; H01J1/02; H01J1/34; H10; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2921; H10P14/2926; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3211; H10P14/3214; H10P14/3218; H10P14/3242; H10P14/3244; H10P14/3248; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H01J2201/00; H01J2201/34; H01J2201/342; H01J2201/3421; H01J2201/3423; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/056; Y10S148/059; Y10S148/064; Y10S148/065; Y10S148/067; Y10S148/072; Y10S148/115; Y10S148/119; Y10S148/12; Y10S148/15
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
21 words
The electron emitter defined in claim 1 wherein said substrate is spinel having said major surface in the (100) crystallographic plane.
Claim 2
Dependent Claim
21 words
The electron emitter defined in claim 1 wherein said substrate is sapphire having said major surface in the (1102) crystallographic plane.
Claim 3
Dependent Claim
14 words
The electron emitter defined in claim 1 wherein said third layer is gallium arsenide.
Claim 4
Dependent Claim
13 words
The electron emitter defined in claim 3 wherein said first layer is silicon.
Claim 5
Dependent Claim
14 words
The electron emitter defined in claim 5 wherein said second layer is gallium phosphide.
Claim 6
Dependent Claim
15 words
The electron emitter defined in claim 5 wherein said second layer is gallium arsenide phosphide.
Claim 7
Dependent Claim
14 words
The electron emitter defined in claim 6 wherein said third layer is gallium arsenide.
Claim 8
Dependent Claim
172 words
A photoemissive electron tube comprising: an evacuated envelope having a transparent monocrystalline faceplate with a substantially flat inside surface in the interior of said envelope; a first monocrystalline epitaxial layer of material chosen from the group consisting of silicon and germanium on said inside surface of said faceplate, said first layer having a thickness of from about 200 to about 300 nanometers; a second monocrystalline epitaxial layer of a compound chosen from the group consisting of III-V and II-VI semiconductor compounds on said first layer, said second layer having a thickness of at least about 3 microns; a third monocrystalline epitaxial layer of a III-V semiconductor compound on said second layer, said third layer compound having an energy bandgap smaller than said second layer compound, and said third layer having a thickness of from about 1 micron to about 5 microns, the surface of said third layer being sensitized with at least an electropositive material to reduce the work function to a level below said energy bandgap of said third layer compound.
Claim 9
Dependent Claim
22 words
The photoemissive electron tuBe defined in claim 9 wherein said substrate is spinel having said major surface in the (100) crystallographic plane.
Claim 10
Dependent Claim
25 words
The photoemissive electron tube defined in claim 9 wherein said substrate is alpha type aluminum oxide having said major surface in the (1102) crystallographic plane.
Claim 11
Dependent Claim
16 words
The photoemissive electron tube defined in claim 9 wherein said third layer compound is gallium arsenide.
Claim 12
Dependent Claim
14 words
The photoemissive electron tube defined in claim 11 wherein said first layer is silicon.
Claim 13
Dependent Claim
16 words
The photoemissive electron tube defined in claim 13 wherein said second layer compound is gallium phosphide.
Claim 14
Dependent Claim
17 words
The photoemissive electron tube defined in claim 13 wherein said second layer compound is gallium arsenide phosphide.
Claim 15
Dependent Claim
16 words
The photoemissive electron tube defined in claim 14 wherein said third layer compound is gallium arsenide.
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) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |