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CN-120236951-B - Electron source, preparation method and application thereof

CN120236951BCN 120236951 BCN120236951 BCN 120236951BCN-120236951-B

Abstract

The application provides an electron source and a preparation method and application thereof, wherein the electron source comprises an optical fiber, a conductive connecting layer and an electron emission layer, the conductive connecting layer is arranged on the outer surface of the optical fiber, the electron emission layer comprises an electron excitation layer electrically connected with the conductive connecting layer, the electron excitation layer comprises at least one layer of two-dimensional material, the electron excitation layer is arranged on a laser emergent path of the optical fiber, and laser emergent from the optical fiber can directly irradiate on the electron excitation layer so that the electron excitation layer is excited by the laser and emits electrons. The two-dimensional material used as the material of the electron emission layer has the characteristics of good stability, long service life and the like, can be directly integrated with the optical fiber, can provide a stable excitation source with adjustable wavelength, polarization and optical mode, and can be suitable for different application scenes.

Inventors

  • YAO GUANGJIE
  • Liu Huazhan
  • HONG HAO
  • YOU YILONG
  • LIU KAIHUI

Assignees

  • 北京大学

Dates

Publication Date
20260508
Application Date
20231229

Claims (12)

  1. 1. An electron source, characterized in that the electron source comprises an optical fiber, a conductive connecting layer and an electron emission layer, wherein the conductive connecting layer is arranged on the outer surface of the optical fiber; The electron emission layer is arranged on the laser emergent surface of the optical fiber, and comprises an electron excitation layer electrically connected with the conductive connecting layer, and the electron excitation layer comprises at least one layer of two-dimensional material; The electronic excitation layer is arranged on a laser emergent path of the optical fiber, and laser emergent from the optical fiber can directly irradiate the electronic excitation layer, so that the electronic excitation layer is excited by the laser to generate photoelectric effect and emit electrons.
  2. 2. The electron source of claim 1, wherein the electron excitation layer satisfies at least one of the following conditions: (1) The thickness of the electron excitation layer is 0.1 nm-100 nm; (2) The thickness of the two-dimensional material is 0.1 nm-50 nm; (3) The two-dimensional material includes at least one of graphene, transition metal chalcogenide, two-dimensional perovskite, two-dimensional diamond, and boron nitride.
  3. 3. The electron source according to claim 1, wherein the electron excitation layer comprises at least two layers of two-dimensional materials which are sequentially stacked along the laser emission direction of the optical fiber, the two-dimensional materials are conductive two-dimensional materials, and two adjacent layers of the two-dimensional materials are the same or different.
  4. 4. An electron source according to claim 3 wherein the crystal axis angle between adjacent layers of the two-dimensional material is in the range 0 ° to 360 °.
  5. 5. The electron source of claim 1, wherein the electron excitation layer is formed by splicing at least two different two-dimensional materials, and the laser of the optical fiber is irradiated to a splice adjacent to the two-dimensional materials.
  6. 6. The electron source of claim 1, wherein the optical fiber is a solid core optical fiber, a tip optical fiber, a side-cut optical fiber, or a holey optical fiber.
  7. 7. The electron source according to any of claims 1 to 6, wherein the electron emission layer further comprises an auxiliary layer disposed on a side of the electron excitation layer adjacent to the optical fiber, or The auxiliary layer is arranged on one side of the electronic excitation layer, which is far away from the optical fiber.
  8. 8. The electron source of claim 7, wherein the auxiliary layer comprises a transparent support layer, the material of the transparent support layer comprising at least one of boron nitride, mica, and diamond; the thickness of the transparent supporting layer is 0.1-1000 nm, and the light transmittance is more than or equal to 10%.
  9. 9. The electron source of claim 7, wherein the auxiliary layer comprises a conductive support layer, the electron excitation layer being electrically connected to the conductive connection layer through the conductive support layer; the material of the conductive supporting layer comprises at least one of conductive metal and graphene; the thickness of the conductive supporting layer is 0.1 nm-100 nm.
  10. 10. A method of preparing the electron source according to any one of claims 1 to 9, comprising: And forming an electron excitation layer formed by at least one layer of two-dimensional material on the laser emergent path of the optical fiber, and forming a conductive connecting layer electrically connected with the electron excitation layer on the outer surface of the optical fiber to prepare the electron source.
  11. 11. An electron gun comprising a housing, a grid, an anode, and the electron source of any of claims 1-9; The electron source is fixed in the shell, and the grid and the anode are sequentially arranged on the electron exit side of the electron source.
  12. 12. Use of an electron source according to any of claims 1-9, wherein the use of the electron source comprises at least one of an electron microscope, an electron beam exposure machine, an X-ray tube, a free electron laser and a display.

Description

Electron source, preparation method and application thereof Technical Field The invention relates to the technical field of electron sources, in particular to an electron source and a preparation method and application thereof. Background The electron source is a device for generating vacuum electrons, and conventional electron sources are mainly classified into a heat-emitting electron source, a field-emitting electron source, and a light-emitting electron source according to an excitation manner. The heat emission electron source mainly selects a metal material, and electrons are thermally excited to separate from the surface of the material to form vacuum electrons when the heat emission electron source is heated to thousands of degrees centigrade. The field emission electron source mainly selects a metal needle point, and generates a tip discharge effect under the action of a strong electric field applied from the outside. The light-emitting electron source uses a metal material as a photocathode, and irradiates the photocathode material with laser light to generate electrons. However, the electron source in the conventional technology cannot achieve both the emission efficiency and the stability, and how to provide an electron source with high electron emission efficiency and good stability is a technical problem that needs to be solved urgently at present. Disclosure of Invention Based on this, it is necessary to provide an electron source capable of having high electron emission efficiency and good stability, and a method for producing the same and applications thereof. In a first aspect, the present application provides an electron source comprising an optical fiber, a conductive connection layer, and an electron emission layer, the conductive connection layer being disposed on an outer surface of the optical fiber; The electron emission layer comprises an electron excitation layer electrically connected with the conductive connection layer, and the electron excitation layer comprises at least one layer of two-dimensional material; The electron excitation layer is arranged on a laser emergent path of the optical fiber, and laser emergent from the optical fiber can directly irradiate the electron excitation layer, so that the electron excitation layer is excited by the laser and emits electrons. In some embodiments, the thickness of the electron excitation layer is 0.1nm to 100nm. In some embodiments, the thickness of the two-dimensional material is 0.1nm to 50nm. In some embodiments, the two-dimensional material includes at least one of graphene, a transition metal chalcogenide, a two-dimensional perovskite, a two-dimensional diamond, and boron nitride. In some embodiments, the electron excitation layer includes at least two layers of two-dimensional materials sequentially stacked along the laser emitting direction of the optical fiber, and the two-dimensional materials are both conductive two-dimensional materials. In some embodiments, adjacent two layers of the two-dimensional material are the same or different. In some embodiments, the crystal axis included angle of two adjacent layers of the two-dimensional material is 0-360 degrees. In some embodiments, the electronic excitation layer is formed by splicing at least two different two-dimensional materials, and the laser of the optical fiber irradiates the splice of the two-dimensional materials. In some embodiments, the electron emission layer further comprises an auxiliary layer disposed on a side of the electron excitation layer adjacent to the optical fiber, or The auxiliary layer is arranged on one side of the electronic excitation layer, which is far away from the optical fiber. In some embodiments, the auxiliary layer includes a transparent support layer, and a material of the transparent support layer includes at least one of boron nitride, mica, and diamond. In some embodiments, the transparent support layer has a thickness of 0.1nm to 1000nm and a light transmittance of 10% or more. In some embodiments, the auxiliary layer includes a conductive support layer through which the electron excitation layer is electrically connected to the conductive connection layer. In some embodiments, the material of the conductive support layer includes at least one of a conductive metal and graphene. In some embodiments, the conductive support layer has a thickness of 0.1nm to 100nm. In some embodiments, the optical fiber is a solid core optical fiber, a tip optical fiber, a side-cut optical fiber, or a holey optical fiber. In a second aspect, the present application provides a method for preparing an electron source according to the first aspect, the method comprising: And forming an electron excitation layer formed by at least one layer of two-dimensional material on the laser emergent path of the optical fiber, and forming a conductive connecting layer electrically connected with the electron excitation layer on the outer surface of the optical fiber