A single carbon nano electronic field emission cathode and its making method

A technology of carbon nanotubes and emission cathodes, which is applied in the field of preparation of such carbon nanotube electron field emission cathodes, can solve the problems of small current and difficulty in obtaining single-walled tubes, and achieve the effects of large current, easy acquisition, and low turn-on voltage

Inactive Publication Date: 2008-09-10
PEKING UNIV
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Problems solved by technology

However, the current that single-walled carbon nanotubes can withstand is small, and t...

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  • A single carbon nano electronic field emission cathode and its making method
  • A single carbon nano electronic field emission cathode and its making method
  • A single carbon nano electronic field emission cathode and its making method

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Embodiment Construction

[0032] The present invention will be further described below in conjunction with the accompanying drawings.

[0033] The invention adopts the method of in-situ electrifying a single carbon nanotube in a transmission electron microscope to prepare the carbon nanotube with a conical tip. The conical tip of this carbon nanotube has the diameter and the number of tube walls of an ordinary multi-walled carbon nanotube, while the conical tip is composed of a closed single-walled or double-walled tube, and its topmost curvature radius is equivalent to that of an ordinary single-walled carbon nanotube. wall pipe. refer to figure 1 , a single multi-walled carbon nanotube rides on two metal wires, such as figure 1 As shown in (a), under the action of electric heating, the middle part of the carbon nanotube gradually becomes thinner, and finally breaks into two carbon nanotubes with conical tips, as shown in figure 1 Shown in (b). figure 1 (c) records the current-voltage curve of the...

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Abstract

The invention provides an electron field emission cathode of a single carbon nanotube and a method for the preparation thereof, belonging to the application field of the carbon nanotubes. The nanotube used as the field emission cathode is provided with a cone-shaped end part that is in structure of a sealed sing-wall or double-wall pipe; multi-wall pipe structure is arranged at the lower part of the cone-shaped structure. The manufacturing method of the carbon nanotubes comprises the steps as follows: a multi-wall carbon nanotube is acquired through a metal wire; one multi-wall carbon nanotube on the metal wire is contacted through a metal needle tip; evenly increasing voltage is added between the metal wire and the metal needle tip, which leads the single carbon nanotube to become thinner and even to break up as a result of the electric current effects, so as to obtain the carbon nanotube with the cone-shaped end part. The carbon nanotube, with the advantages of the single-wall tubes and the multi-wall tubes on the emission performance, also has the advantages of stable emission, and low threshold voltage, can bear higher electric current and is also relatively easy to obtain. In addition, the curvature radius of the cone-shaped tip is controllable and can be enlarged; therefore, the corresponding maximum electric current to be borne can be increased constantly.

Description

technical field [0001] The invention belongs to the application field of carbon nanotubes. The carbon nanotubes can be used as a single electron field emission cathode, and also relates to a method for preparing the carbon nanotube electron field emission cathode. Background technique [0002] Carbon nanotubes have become very competitive materials for electron field emission cathodes due to their unique morphology and superior performance. At present, some products using carbon nanotubes as emission cathodes have entered practical use, such as high-brightness lighting equipment and X-ray tubes. In addition, carbon nanotube field emission flat panel display devices are also expected to be commercialized. The above field emission devices are all based on arrays or thin films composed of multiple carbon nanotubes. In fact, a single carbon nanotube as a field emission source also has a good application prospect. A single carbon nanotube can withstand a large current density, ...

Claims

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Application Information

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IPC IPC(8): H01J1/304H01J9/02
Inventor 王鸣生彭练矛陈清
Owner PEKING UNIV
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