US3932883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photocathodes
Assignee: UK Secretary of State for Defence
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Filing: 1974-06-24
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Granted: 1976-01-13
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Expires: 1994-06-24
Abstract
Abstract A transmission photocathode comprising a crystal substrate transparent to the radiation to be detected, at least one epitaxial crystalline intermediate layer having a lattice constant close to that of the detector layer and transparent to the radiation to be detected, and a p-type group III-V compound detector layer. Preferably the intermediate layer is p-type.
Inventors
- 👤 Michael Charles Rowland
- 👤 David Robert Wight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:00
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/34; H01J2201/00; H01J2201/34; H01J2201/342; H01J2201/3421; H01J2201/3423; Y; Y10; Y10S; Y10S148/00; Y10S148/005; Y10S148/066; Y10S148/067; Y10S148/072
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
93 words
A transmission photocathode comprising: an activated detector layer of p-type gallium arsenide of thickness less than the electron diffusion length in gallium arsenide, a crystalline substrate of gallium phosphide having an energy band gap greater than that of said gallium arsenide detector layer, and a p-type intermediate layer selected from the group consisting of Ga.sub.(1 -x ) Al x As, where 0 < x ≦ 1, and Ga 0 .5 In 0 .5 P, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
Claim 2
Dependent Claim
93 words
A transmission photocathode comprising: an activated detector layer of p-type gallium arsenide of thickness less than the electron diffusion length in gallium arsenide, a crystalline substrate of gallium phosphide having an energy band gap greater than that of said gallium arsenide detector layer, and a p-type intermediate layer selected from the group consisting of Ga.sub.(1 -x ) Al x As, where 0 < x ≦ 1, and Ga 0 .5 In 0 .5 P, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
Claim 3
Dependent Claim
12 words
The transmission photocathode of claim 1 wherein 0.4 ≦ x ≦ 1.
Claim 4
Dependent Claim
10 words
The transmission photocathode of claim 2 wherein x = 0.7.
Claim 5
Dependent Claim
111 words
A transmission photocathode comprising: an activated detector layer of p-type photocathodic material having a thickness less than the electron diffusion length in said photocathodic material, said photocathic material being selected from the group consisting of gallium indium arsenide and gallium arsenide antimonide, a crystalline substrate of gallium phosphide having an energy band gap greater than that of the detector layer, and an intermediate layer comprising p-type gallium indium phosphide having a lattice constant within 0.2% of said detector layer and having an energy band gap greater than that of the detector layer, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
Claim 6
Dependent Claim
111 words
A transmission photocathode comprising: an activated detector layer of p-type photocathodic material having a thickness less than the electron diffusion length in said photocathodic material, said photocathic material being selected from the group consisting of gallium indium arsenide and gallium arsenide antimonide, a crystalline substrate of gallium phosphide having an energy band gap greater than that of the detector layer, and an intermediate layer comprising p-type gallium indium phosphide having a lattice constant within 0.2% of said detector layer and having an energy band gap greater than that of the detector layer, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
Claim 7
Dependent Claim
68 words
A transmission photocathode comprising: an activated detector layer of p-type gallium arsenide having a thickness less than the electron diffusion length in gallium arsenide, a gallium phosphide substrate, and an intermediate layer comprising Ga 0 .3 Al 0 .7 As including a p-type dopant, said p-type dopant being zinc, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
Claim 8
Dependent Claim
68 words
A transmission photocathode comprising: an activated detector layer of p-type gallium arsenide having a thickness less than the electron diffusion length in gallium arsenide, a gallium phosphide substrate, and an intermediate layer comprising Ga 0 .3 Al 0 .7 As including a p-type dopant, said p-type dopant being zinc, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
Claim 9
Dependent Claim
68 words
A transmission photocathode comprising: an activated detector layer of p-type gallium arsenide having a thickness less than the electron diffusion length in gallium arsenide, a gallium phosphide substrate, and an intermediate layer comprising Ga 0 .5 In 0 .5 P including a p-type dopant, said p-type dopant being zinc, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
Claim 10
Dependent Claim
68 words
A transmission photocathode comprising: an activated detector layer of p-type gallium arsenide having a thickness less than the electron diffusion length in gallium arsenide, a gallium phosphide substrate, and an intermediate layer comprising Ga 0 .5 In 0 .5 P including a p-type dopant, said p-type dopant being zinc, said detector layer being epitaxially supported upon said intermediate layer, and said intermediate layer being supported upon said substrate.
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) | 1979-01-12 | 1979-07-14 | 1980-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-12 | 1983-07-14 | 1984-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-12 | 1987-07-14 | 1988-01-13 | $7700.00 | Window Closed / Lapsed |