Patent US3575628A successfully refreshed from Google Patents.
US3575628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmissive photocathode and devices utilizing the same
Assignee: Westinghouse Electric Corp
•
Filing: 1968-11-26
•
Granted: 1971-04-20
•
Expires: 1988-11-26
Abstract
Abstract Described are transmissive gallium arsenide photocathodes, and optical devices utilizing the same, comprising gallium arsenide epitaxially deposited on a layer of silicon, the gallium arsenide having absorbed into its surface electropositive metal atoms, preferably cesium. In one embodiment of the invention, the gallium arsenide is deposited on a silicon film epitaxially deposited on a transparent sapphire substrate; while in another embodiment, the gallium arsenide is deposited on a thin silicon web having a thickness in the range of about 10 to 25 microns.
Inventors
- 👤 James C Word
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:19
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/34; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J2201/00; H01J2201/34; H01J2201/342; H01J2201/3421; H01J2201/3423; Y; Y10; Y10S; Y10S148/00; Y10S148/056; Y10S148/059; Y10S148/065; Y10S148/067; Y10S148/072; Y10S148/15; Y10S438/00; Y10S438/914; Y10S438/918
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
85 words
In an optical device, an evacuated enclosure, a photoemitting cathode within said enclosure, an anode within said enclosure having a photoemissive phosphor thereon, and means for establishing an electrical potential between said anode and cathode, said cathode comprising a single crystal gallium arsenide deposited on a transparent substrate said cathode arranged in said enclosure with said transparent substrate positioned to receive and transmit incident light which strikes the gallium arsenide on one side with electrons being emitted from the gallium arsenide on the other side.
Claim 2
Dependent Claim
85 words
In an optical device, an evacuated enclosure, a photoemitting cathode within said enclosure, an anode within said enclosure having a photoemissive phosphor thereon, and means for establishing an electrical potential between said anode and cathode, said cathode comprising a single crystal gallium arsenide deposited on a transparent substrate said cathode arranged in said enclosure with said transparent substrate positioned to receive and transmit incident light which strikes the gallium arsenide on one side with electrons being emitted from the gallium arsenide on the other side.
Claim 3
Dependent Claim
22 words
The device of claim 1 wherein said transparent substrate comprises a wafer of sapphire having deposited thereon an epitaxial layer of silicon.
Claim 4
Dependent Claim
53 words
The device of claim 1 wherein said cathode comprises a plurality of silicon webs having a thickness in the range of about 10 to 25 microns with each of said webs having a layer of gallium arsenide epitaxially deposited thereon, and means for connecting said webs in parallel to said source of potential.
Claim 5
Dependent Claim
25 words
The device of claim 1 wherein said transparent substrate comprises a silicon web having a thickness in the range of about 10 to 25 microns.
Claim 6
Dependent Claim
18 words
The device of claim 1 including a monatomic layer of cesium deposited on said layer of gallium arsenide.
Claim 7
Dependent Claim
13 words
The device of claim 2 wherein said epitaxial layer of silicon is monocrystalline.
Claim 8
Dependent Claim
15 words
The device of claim 6 wherein said layer of monocrystalline silicon has a (111) orientation.
Claim 9
Dependent Claim
30 words
The device of claim 7 wherein said layer of gallium arsenide is heavily doped to greater than 1019 carriers per cubic centimeter to provide a semiconductive material of P-type conductivity.
Claim 10
Dependent Claim
36 words
The device of claim 8 wherein said silicon layer has a thickness no greater than 200 Angstrom units and said gallium arsenide layer has a thickness in the range of about 1 to 10,000 Angstrom units.
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) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |