Transmission mode photocathode

Patent metadata

Field	Value
Publication number	US-9824844-B2
Application number	US-201415029336-A
Country	US
Kind code	B2
Filing date	Aug 8, 2014
Priority date	Nov 1, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A transmission mode photocathode comprises: an optically transparent substrate having an outside face to which light is incident, and an inside face from which the light incident to the outside face side is output; a photoelectric conversion layer disposed on the inside face side of the optically transparent substrate and configured to convert the light output from the inside face into a photoelectron or photoelectrons; and an optically-transparent electroconductive layer comprising graphene, and disposed between the optically transparent substrate and the photoelectric conversion layer.

First claim

The invention claimed is:

1. A transmission mode photocathode comprising:
an optically transparent substrate having one face to which light is incident, and another face from which the light incident to the one face is output;
a photoelectric conversion layer disposed on the other face side of the optically transparent substrate and configured to convert the light output from the other face into a photoelectron or photoelectrons; and
an optically-transparent electroconductive layer comprising graphene, and disposed between the optically transparent substrate and the photoelectric conversion layer; wherein
the optically-transparent electroconductive layer covers a region through which the light is transmitted when viewed from a thickness direction of the optically transparent substrate, and
the photoelectric conversion layer covers a portion of the optically-transparent electroconductive layer overlapping the region.

2. The transmission mode photocathode according to claim 1 , wherein the optically-transparent electroconductive layer is comprised of a single layer of graphene.

3. The transmission mode photocathode according to claim 1 , wherein the optically-transparent electroconductive layer is comprised of multiple layers of graphene.

4. The transmission mode photocathode according to claim 1 , wherein the photoelectric conversion layer covers the whole of the optically-transparent electroconductive layer when viewed from the thickness direction.

5. The transmission mode photocathode according to claim 1 , wherein the optically-transparent electroconductive layer contacts the other surface of the optically transparent substrate.

6. The transmission mode photocathode according to claim 1 , wherein the photoelectric conversion layer forms a photoelectric surface consisting primarily of an alkali metal.

7. A transmission mode photocathode comprising:
an optically transparent substrate having one face to which light is incident, and another face from which the light incident to the one face is output;
a photoelectric conversion layer disposed on the other face side of the optically transparent substrate and configured to convert the light output from the other face into a photoelectron or photoelectrons; and
an optically-transparent electroconductive layer comprising graphene, and disposed between the optically transparent substrate and the photoelectric conversion layer; wherein
the optically-transparent electroconductive layer contacts the other surface of the optically transparent substrate, and
the photoelectric conversion layer forms a photoelectric surface consisting primarily of an alkali metal.

8. The transmission mode photocathode according to claim 7 , wherein the photoelectric conversion layer covers the whole of the optically-transparent electroconductive layer when viewed from a thickness direction of the optically transparent substrate.

9. The transmission mode photocathode according to claim 7 , wherein the optically-transparent electroconductive layer is comprised of a single layer of graphene.

10. The transmission mode photocathode according to claim 7 , wherein the optically-transparent electroconductive layer is comprised of multiple layers of graphene.

11. An electron tube comprising a hermetic vessel, the hermetic vessel including an optically transparent substrate having one face to which light is incident and another face from which the light incident to the one face is output, and a side tube to which the optically transparent substrate is fixed; the electron tube further comprising:
a photoelectric conversion layer disposed on the other face side of the optically transparent substrate and configured to convert the light output from the other face into a photoelectron or photoelectrons;
an optically-transparent electroconductive layer comprising graphene, and disposed between the optically transparent substrate and the photoelectric conversion layer; and
an contact portion contacting the side tube and the optically-transparent electroconductive layer; wherein
the photoelectric conversion layer covers at least a part of the side tube, the optically-transparent electroconductive layer, and the contact portion when viewed from a thickness direction of the optically transparent substrate.

12. The electron tube according to claim 11 , wherein the side tube comprises a metal.

13. The electron tube according to claim 11 , wherein
the side tube has a flange portion fixed to the other face of the optically transparent substrate, and
the photoelectric conversion layer covers at least a part of the flange portion when viewed from the thickness direction.

14. The electron tube according to claim 11 , wherein the optically-transparent electroconductive layer contacts the other surface of the optically transparent substrate.

15. The electron tube according to claim 11 , wherein the photoelectric conversion layer forms a photoelectric surface consisting primarily of an alkali metal.

16. The electron tube according to claim 11 , wherein the photoelectric conversion layer covers the whole of the optically-transparent electroconductive layer when viewed from the thickness direction.

17. The electron tube according to claim 11 , wherein the optically-transparent electroconductive layer is comprised of a single layer of graphene.

18. The electron tube according to claim 11 , wherein the optically-transparent electroconductive layer is comprised of multiple layers of graphene.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Nagata Takaaki
• Hamana Yasumasa
• Nakamura Kimitsugu

Classifications

• H01J1/34 Primary

  Photo-emissive cathodes (H01J1/35 takes precedence) · CPC title

• H01J1/32

  Secondary-electron-emitting electrodes (H01J1/35 takes precedence) · CPC title

• H01J43/10

  Dynodes (H01J43/24, H01J43/26 take precedence) · CPC title

• H01J43/08

  Cathode arrangements (construction of photo cathodes H01J40/06, H01J40/16, H01J47/00, H01J49/08) · CPC title

• H01J40/06

  Photo-emissive cathodes · CPC title