Field emission cathode having an electrically conducting material shaped of a narrow rod or knife edge

• US RE38,223 E1
• Filed: 02/15/2000
• Issued: 08/19/2003
• Est. Priority Date: 02/23/1994
• Status: Expired due to Term

• Current Assignee: Till Keesmann
• Original Assignee: Till Keesmann
• Inventors: Keesmann, Till, Grosse-Wilde, Hubert
• Primary Examiner(s): DAY, MICHAEL HENRY
• Application Number:
  US09/504,635
• Time in Patent Office: 1,281 Days
• Field of Search: 313/309, 313/336, 313/351, 313/495, 313/496, 313/497, 445/50, 445/51
• US Class Current: 313/309
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01J 1/3042 microengineered, e.g. Spindt-type
• CPC Class Codes: H01J 2201/30423 Microengineered edge emitters
• CPC Class Codes: H01J 2201/30469 Carbon nanotubes (CNTs)
• CPC Class Codes: Y10S 977/876 Nanotube tip
• CPC Class Codes: Y10S 977/939 Electron emitter, e.g. spindt emitter tip coated with nanoparticles

Abstract

A field emission cathode device consisting of an electrically conducting material and with a narrow, rod-shaped geometry or a knife edge, to achieve a high amplification of the electric field strength is characterized in that the electron-emitting part of the field emission cathode at least partly has preferred cylindrical host molecules and/or compounds with host compounds and/or cylindrical atomic networks, possibly with end caps with diameters measuring in the nanometer range.

Claims

1. A field emission cathode which consists of an electrically conducting material having the shape of a narrow rod or a knife edge to achieve high magnification of the electric field strength, such that the electron-emitting part of the field emission cathode has cylindrical molecules formed at least in part as single-shell or multiple-shell carbon nano-cylinders.

2. The device of claim 1, wherein the carbon nano-cylinders have end caps.

3. The device of claim 1, wherein the single- or multiple-shell carbon nano-cylinders are collected into bundles.

4. The device of claim 1, wherein the carbon nano-cylinders are filled with metal.

5. The device of claim 1, wherein the carbon nano-cylinders at least partly have endohedral or exohedral compounds with other atoms or molecules.

6. The device of claim 1, wherein the field emission cathode forms the tip of a field electron microscope, a field ion microscope, a scanning tunnel microscope, or a scanning power microscope.

7. The device of claim 1, wherein a plurality of similar field emission cathodes is disposed in a line or a plane, and thereby forms a linear or planar electron source.

8. The device of claim 1, wherein a plurality of similar field emission cathodes is disposed in a plane in the form of a matrix, and the field emission cathodes can be driven individually, and the field emission cathodes represent the electron sources for the image points of a visual display system.

9. The device of claim 8, wherein the plurality of similar field emission cathodes is in the range of 10,000 to 100,000 molecules.

10. A field emission cathode comprising an electron-emitting part which is formed at least in part as a carbon nano-cylinder, wherein the carbon nano-cylinder serves as a coating over a cathode tip structure.

11. A field emission cathode comprising:

12. The field emission cathode of claim 11, wherein the carbon nano-cylinder comprises a single-walled carbon nano-cylinder.

13. The field emission cathode of claim 11, wherein the carbon nano-cylinder comprises a multi-walled carbon nano-cylinder.

14. The field emission cathode of claim 11, wherein the carbon nano-cylinder at its end cap is open.

15. The field emission cathode of claim 11, wherein the conducting material is in a form of a cone.

16. The field emission cathode of claim 11, further comprising: