Claims
- 1. A photoemission device, comprising:
- a p-type semiconductor for absorbing incident photons to excite photoelectrons;
- an insulator layer being layered on and in direct contact with one surface of said p-type semiconductor said insulator having a predetermined pattern so as to expose a predetermined region of said one surface of said p-type semiconductor;
- a metal layer layered on and in direct contact with said one surface of said p-type semiconductor, said metal layer coating said exposed region of said one surface on which said insulator layer is not layered;
- a lead electrode layered on said insulator layer and being spaced from said metal layer through said insulator layer; and
- a contact layer for applying a predetermined polarity voltage between said lead electrode and another surface of said p-type semiconductor, said contact layer being formed on said another surface;
- wherein the photoelectrons excited by the incident photons entering said p-type semiconductor and moving toward said one surface of said p-type semiconductor are made to be emitted through said metal layer by an electric field produced between said lead electrode and said one surface of said P-type semiconductor by said predetermined polarity voltage.
- 2. A photoemission device according to claim 1, wherein said metal layer comprises either one of an alkali metal, a compound of the alkali metal, an oxide of the alkali metal, and a fluoride of the alkali metal.
- 3. A photoemission device according to claim 1, wherein said p-type semiconductor has either one of a III-V compound semiconductor, a mixed crystal III-V compound semiconductor, and a hetero structure of III-V compound semiconductors.
- 4. A photoemission device according to claim 1, wherein said p-type semiconductor is formed of GaAs.
- 5. A photoemission device according to claim 1, wherein said p-type semiconductor is formed of GaAs.sub.y P.sub.(1-y) (where 0.ltoreq.y.ltoreq.1).
- 6. A photoemission device according to claim 1, wherein said p-type semiconductor is formed of In.sub.x Ga.sub.(1-x) As.sub.y P.sub.(1-y) (where 0.ltoreq.x.ltoreq.1 and 0.ltoreq.y.ltoreq.1).
- 7. A photoemission device according to claim 1, wherein said p-type semiconductor has a hetero structure of GaAs and Al.sub.x Ga.sub.(1-x) As (where 0.ltoreq.x.ltoreq.1).
- 8. A photoemission device according to claim 1, wherein said p-type semiconductor has a hetero structure of GaAs and In.sub.x Ga.sub.(1-x) As (where 0.ltoreq.x.ltoreq.1).
- 9. A photoemission device according to claim 1, wherein said p-type semiconductor has a hetero structure of InP and In.sub.x Ga.sub.(1-x) As.sub.y P.sub.(1-y) (where 0.ltoreq.x.ltoreq.1 and 0.ltoreq.y.ltoreq.1).
- 10. A photoemission device according to claim 1, wherein said p-type semiconductor has a hetero structure of InP and In.sub.x Al.sub.y Ga.sub.�1-(x+y)! As (where 0.ltoreq.x.ltoreq.1 and 0.ltoreq.y.ltoreq.1).
- 11. A photoemission device according to claim 1, wherein said p-type semiconductor has either one of p-type Si, p-type Ge, a mixed crystal of p-type Si, a mixed crystal of p-type Ge, and hetero structures thereof.
- 12. A photoemission device according to claim 1, wherein said p-type semiconductor has a carrier density within the range of about 1.times.10.sup.18 to about 5.times.10.sup.19 (cm.sup.-3).
- 13. A photoemission device according to claim 1, wherein said insulator layer has either one of SiO.sub.2, Si.sub.3 N.sub.4, Al.sub.2 O.sub.3, and lamination structures thereof.
- 14. A photoemission device according to claim 2, wherein said alkali metal is either one of Cs, K, Na, and Rb.
- 15. An electron tube comprising:
- the photoemission device as set forth in claim 1; and
- an electron multiplier for electron-multiplying photoelectrons emitted from said photoemission device.
- 16. An electron tube according to claim 15, wherein said electron multiplier comprises dynodes.
- 17. An electron tube according to claim 15, wherein said electron multiplier comprises a microchannel plate.
- 18. An electron tube comprising:
- the photoemission device as set forth in claim 2; and
- an electron multiplier for electron-multiplying photoelectrons emitted from said photoemission device.
- 19. An electron tube according to claim 18, wherein said electron multiplier comprises dynodes.
- 20. An electron tube according to claim 18, wherein said electron multiplier comprises a microchannel plate.
- 21. A photodetecting apparatus comprising:
- the electron tube as set forth in claim 15; and
- signal processing means for signal-processing an output from said electron tube.
- 22. A photodetecting apparatus comprising:
- the electron tube as set forth in claim 18; and
- signal processing means for signal-processing an output from said electron tube.
Priority Claims (2)
Number |
Date |
Country |
Kind |
5-218609 |
Sep 1993 |
JPX |
|
5-226237 |
Sep 1993 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 08/299,664, filed Sep. 2, 1994 now U.S. Pat. No. 5,591,986.
US Referenced Citations (10)
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Continuations (1)
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Number |
Date |
Country |
Parent |
299664 |
Sep 1994 |
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