TWI386964B - Electron emitter and displaying device using the same - Google Patents

Description

Electron emitting device and display device

The present invention relates to an electron emission device and a display device using the same.

The electron emission display device is a new generation of emerging technology. Compared with the previous display device, the electron emission display device has the advantages of high brightness, high efficiency, large viewing angle, low power consumption and small volume, and thus the electron emission display device is widely used. It is used in small-sized display fields such as automobiles, home audio-visual appliances, and industrial instruments.

The structure of the prior art electron emission display device can be classified into a two-pole type and a three-pole type. The two-electrode type electron-emitting display device includes an anode and a cathode. This structure is difficult to control due to the necessity of applying a high voltage, and uniformity and electron emission are only suitable for character display, and is not suitable for graphic and image display. The triode structure is based on the improvement of the two-pole structure. The gate is added to control the electron emission, and electrons can be emitted under a lower voltage condition, and the electron emission is easily controlled by the gate. Therefore, in the three-electrode type electron-emitting display device, such an electron-emitting device composed of a cathode for generating electrons and a gate for extracting electrons and accelerating electrons has become a commonly used electron-emitting device.

Previous electron-emitting devices typically included a cathode, an insulating support, and a grid. The cathode includes a plurality of electron emitters. The insulating support is disposed on the cathode, and the electron emitter has a through hole. The gate is disposed on the insulating support, and the electron emitter has a through hole. When used, different voltages are applied to the gate and cathode, and electrons are emitted from the electron emitter and are worn. The through hole of the insulating support and the gate is emitted.

In the prior art electron-emitting devices, the gate thereof often employed a porous metal grid structure. The plurality of meshes on the metal grid are the gate holes of the gate, and the aperture of the gate holes should be as small as possible. This is because the tiny gate holes can not only form a more uniform space electric field inside and outside the gate holes, but also reduce the gate. Voltage, which reduces the divergence of the electron beam (see "Analog of Field Emission Cathode with Tiny Gate Aperture", Song Cuihua, Vacuum Electronics Technology, Field Emission and Vacuum Microelectronics Conference Album, 2006). Such a metal gate has the following disadvantages: First, due to process conditions, the mesh of the metal grid structure is generally produced by photolithography or chemical etching (see "New Type Gate Electrode of CNT- FED Fabricated by Chemical Corrosive method", Chen Jing, Journal of Southeast University, V23, P241 (2007)), the pore diameter is generally greater than 10 microns, so the spatial electric field uniformity inside and outside the gate grid hole cannot be further improved, and thus cannot be further improved. The uniformity of the speed at which the electron-emitting device emits electrons; secondly, in order to increase the transmittance of electrons, the grid should increase the aperture and reduce the wire diameter as much as possible, but this result reduces the mechanical strength of the grid and makes the gate life Thirdly, the metal grid has a relatively high density and a large mass, so that the mass of the electron-emitting device is large, which limits the application of the electron-emitting device.

Therefore, it is necessary to provide an electron-emitting device that emits electrons at a uniform speed, has a high electron emission rate, and has a large mechanical strength and a small mass, and a display device using the electron-emitting device.

An electron emission device comprising a cathode device and a gate, the gate being spaced apart from the cathode device and electrically insulated from the cathode device, wherein the gate is a carbon nanotube layer, the nano The carbon nanotube layer includes a plurality of long carbon nanotube structures.

A display device using the above electron emission device, comprising a cathode device, an anode device disposed opposite to the cathode device, a gate disposed between the cathode device and the anode device, and the cathode device and the The anode device is spaced apart, wherein the gate comprises a carbon nanotube layer, and the carbon nanotube layer comprises a plurality of carbon nanotube long-line structures.

Compared with the prior art, the electron emission device provided by the present technical solution and the display device using the electron emission device adopt a carbon nanotube layer as a gate, which has the following advantages: First, the gate hole distribution of the gate Uniform, and small aperture, a uniform electric field can be formed between the gate and the cathode, so that the electron emission device and the electron emission speed are uniform, and the electron transmittance is high; second, the gate includes a plurality of The long carbon wire of the carbon nanotubes, the long-term mechanical strength of the carbon nanotubes is large, so the electron-emitting device has a long life; thirdly, since the carbon nanotube layer as the gate has a low density and a light weight, the electron emission is The quality of the device is relatively small and can be easily applied to various fields.

The invention will be further described in detail below with reference to the drawings and specific embodiments.

Referring to FIG. 1 and FIG. 2 , an embodiment of the present technical solution provides an electron emission device 10 including a substrate 12 , a cathode device 14 disposed on the substrate 12 , and an insulating support body 20 . Insulating branch The support 20 is disposed on the substrate 12; a gate 22 disposed on the insulating support 20, spaced apart from the cathode device 14 by the insulating support 20, and electrically insulated from the cathode device 14.

The shape of the substrate 12 is not limited. Preferably, the substrate 12 is an elongated rectangular parallelepiped, and the material of the substrate 12 is an insulating material such as glass, ceramic or cerium oxide. In this embodiment, the insulating substrate 12 is preferably a ceramic plate.

The cathode device 14 includes a cold cathode device and a hot cathode device, and the specific structure thereof is not limited. The cathode device 14 includes a plurality of electron emitters 18, and the specific structure of the electron emitters 18 is not limited, and may be an array or other predetermined pattern of electron emitters. In this embodiment, the cathode device 14 is preferably a cold cathode device comprising a conductive layer 16 and a plurality of electron emitters 18, the plurality of electron emitters 18 being uniformly distributed and vertically disposed on the conductive layer 16, It is electrically connected to the conductive layer 16. The conductive layer 16 is laid on the substrate 12 and has an elongated shape or a strip shape. The conductive layer 16 is made of a metal such as copper, aluminum, gold or silver or indium tin oxide (ITO). The electron emitter 18 is a metal microtip or a carbon nanotube, and other electron emitters can also be used. Preferably, the conductive layer 16 is an elongated ITO film, and the electron emitter 18 is a carbon nanotube.

The insulating support 20 is used to support the gate 22, and its specific shape is not limited. It is only necessary to ensure that the gate 22 is spaced apart from the cathode device 14 and electrically insulated from the cathode device 14. The material of the insulating support 20 is an insulating material such as glass, ceramic or cerium oxide. In the present embodiment, the insulating support body 16 is two strips of the same shape and the same length, which are respectively disposed at both ends of the cathode device 14 and perpendicular to the cathode device 14.

Referring to FIG. 2, the gate 22 is a carbon nanotube layer comprising a plurality of carbon nanotube long-line structures 26, and the plurality of carbon nanotube long-line structures 26 are formed by weaving or directly laying a mesh. Structure or parallel spacing. In the mesh structure, a plurality of carbon nanotube long-line structures 26 are disposed in parallel with the second direction L2 in the first direction L1. An angle α, 0° ≦ α ≦ 90°, is formed between the first direction L1 and the second direction L2. The gate 22 has a thickness of from 2 micrometers to 400 micrometers, and the nanocarbon nanotube fieldline structure 26 has a diameter of from 1 micrometer to 200 micrometers.

The gate 22 includes a plurality of uniformly distributed gate holes 24, and the gate holes 24 of the gate 22 are formed by a carbon nanotube long-line structure 26, and when a plurality of carbon nanotube long-line structures 26 are cross-connected into a network structure, the gates The hole 24 is the mesh of the mesh structure, and the aperture of the gate hole 24 is the aperture of the mesh. When a plurality of carbon nanotube long-line structures 26 are arranged in parallel, the gate hole 24 is the adjacent two carbon nanotube long lines. The gap formed between the structures 26, the aperture of the gate hole 24 is the width of the gap. The aperture size of the gate hole 24 is related to the distance between the carbon nanotube long-line structure 26, so that the pore size distribution of the gate hole 24 is uniform, and the carbon nanotube long-line structure 26 is parallel along the first direction L1 and the second direction L2, respectively. Arranged by spacing. In this embodiment, the distance between the structures of the long carbon nanotubes 28 of the carbon nanotubes is 1 micrometer to 1 centimeter, and the pore diameter of the grid holes 24 is 1 micrometer to 1 centimeter. Preferably, the angle between the first direction L1 and the second direction L2 is 90 degrees, the distance between the long carbon nanotube structures 26 in the first direction L1 and the long-line structure of the carbon nanotubes in the second direction L2 The distance between 26 is 3 micrometers, and the aperture of the gate hole 24 formed by the intersection of the long carbon nanotubes 28 is 3 micrometers.

Referring to FIG. 3, the carbon nanotube long-line structure 26 includes at least one nano carbon tube long line 28, and the nano carbon tube long line 28 has a diameter of 1 micron to 100. Micron. Further, the carbon nanotube long-line structure 26 includes at least two nano carbon tube long wires 28, and the nano carbon tube long wires 28 are twisted into a twisted-type carbon nanotube long-line structure 26 by mechanical external force. Referring to Fig. 4, the long carbon nanotube 28 is a bundle structure consisting of a plurality of carbon nanotube segments arranged in a preferred orientation, or a plurality of twisted and arranged carbon nanotube segments. In the line structure, the adjacent carbon nanotube segments are closely combined by van der Waals force, and the carbon nanotube segments include a plurality of carbon nanotubes of the same length, and the carbon nanotubes are preferentially oriented in the same direction Arranged, the carbon nanotubes are tightly coupled by Van der Waals force.

It can be understood that the arrangement of the carbon nanotubes in the long carbon tube 28 of the carbon nanotubes is not limited, and the carbon nanotubes can be combined with each other by a certain means, such as intertwining or by van der Waals force, to form a certain strength. Nano carbon tube long line 28 can be.

The long carbon nanotube 28 can also be a long line of composite carbon nanotubes formed by combining carbon nanotubes with other materials such as metal particles. The metal particles are filled in the long carbon nanotubes 28 or distributed on the long carbon nanotubes 28 The surface of the composite carbon nanotube has a certain strength and good electrical conductivity.

The carbon nanotubes are a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, or a mixture of any combination thereof. The single-walled carbon nanotube has a diameter of 0.5 nm to 50 nm, the double-walled carbon nanotube has a diameter of 1 nm to 50 nm, and the multi-walled carbon nanotube has a diameter of 1.5 nm to 50 Nano, carbon nanotubes are 10 microns to 5000 microns in length.

The electron-emitting device 10 applies different voltages to the cathode device 14 and the gate 22 respectively when applied (generally, the cathode device is grounded or zero-voltage) The voltage of the gate is from several tens of volts to several hundred volts. The electrons emitted from the electron emitter in the cathode device 14 move in the direction of the gate 22 by the electric field of the gate 22, and are emitted through the gate hole of the gate 22. The electron-emitting device 10 provided by the embodiment of the present technical solution has the following advantages: First, since the gate hole 24 in the gate 22 has a small aperture (at a minimum of 1 micrometer) and is uniformly distributed, the cathode device 14 and the gate are provided. A uniform spatial electric field can be formed between the two, so that the electron emission device 10 emits electrons at a uniform speed and has high electron emission efficiency. Second, the gate electrode 22 includes a plurality of carbon nanotube long-line structures 26 due to the nanometer. The carbon tube long-line structure 26 has high mechanical strength, so the gate 22 has higher mechanical strength, so the electron-emitting device 10 has a longer life; third, the carbon nanotube has a lower density than the metal, so the gate 22 The electron emission device 10 can be conveniently applied to various fields.

Referring to FIG. 5, an embodiment of the present technical solution further provides a display device 300 using the above-described electron emission device 10, comprising: a substrate 302; a cathode device 304 formed on the substrate 302, the cathode device 304 including a plurality of An electron emitter 306 and a conductive layer 318 are disposed on the substrate 302. The electron emitter 306 is disposed on the conductive layer 318 and electrically connected to the conductive layer 318. A first insulating support The first insulating support 308 is disposed on the substrate 302; a gate 310 is formed on the first insulating support 308, and the gate 310 is spaced apart from the cathode device 304 by the first insulating substrate 308; a second insulating support 312, the second insulating support 312 is disposed on the substrate 302; an anode device 320, the anode device 320 includes an anode 314 and a phosphor layer 316, and the anode 314 is disposed in the second Insulating branch On the support 312, the phosphor layer 316 is disposed on the inner surface of the anode 314.

The gate 210 is a carbon nanotube layer, and the carbon nanotube layer comprises a plurality of carbon nanotube long-line structures 26, and the plurality of carbon nanotube long-line structures 26 are arranged to form a grid structure or parallel spacing. Laying, the carbon nanotube layer includes a plurality of uniformly distributed micropores 24.

The specific shape of the second insulating support 312 is not limited, and it is only necessary to ensure that it can support the anode device 320 and the anode device 320 is spaced apart from the cathode device 304 and the gate 310 and electrically insulated from the cathode device 304 and the gate 310. can. The material of the second edge support body 312 is an insulating material such as glass, ceramic or cerium oxide. In the present embodiment, the second insulating support 312 is two elongated strips of the same shape and size, which are respectively disposed at both ends of the cathode device 304 and perpendicular to the cathode device 304.

The anode 314 is disposed on the second insulating support 312, is opposite to the gate 310 at a distance above the gate 310, and is electrically insulated from the gate 310. The anode 314 can be an elongated rectangular parallelepiped, strip or other shape made of ITO conductive glass. It can be understood that the anode 314 can also include a transparent substrate and a conductive layer disposed on a side of the transparent substrate that is closer to the gate 310, that is, an inner surface of the transparent substrate. The phosphor layer 316 is applied to the side of the anode 314 that is closer to the gate 310, that is, the inner surface of the anode 314.

In use, a different voltage is applied between the anode 314, the gate 310 and the cathode 304. After the electrons are emitted from the field emission electron emitter 306, they pass through the gate hole of the gate 310 and then under the electric field formed by the anode 314. Accelerating to the anode 314 and the phosphor layer 316, the excitation phosphor layer 316 emits visible light.

Since the aperture of the gate 310 is small and evenly distributed, a uniform electric field can be formed between the cathode device 304 and the gate 310, and the electron transmittance is high. The display device 300 has high luminous efficiency and is due to nano carbon. Since the tube density is small, the quality of the gate 310 is relatively small, so that the display device 300 is small in mass and can be conveniently applied to various fields.

It can be understood that the display device 300 in this embodiment can implement the light source and the display function respectively according to the different cathode devices 304 and anode devices 320.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

12,302‧‧‧Insert substrate

14,304‧‧‧ cathode device

16,318‧‧‧ Conductive layer

18,306‧‧‧Electronic emitters

20‧‧‧Insulation support

22,310‧‧‧Gate

24‧‧‧ Grid hole

26‧‧‧Nano carbon nanotube long-line structure

28‧‧‧Nano carbon nanotube long line

308‧‧‧First insulation support

312‧‧‧Second insulation support

314‧‧‧Anode

316‧‧‧Fluorescent layer

320‧‧‧Anode device

1 is a schematic structural view of an electron-emitting device according to an embodiment of the present technical solution; and FIG. 2 is a schematic structural view of a gate electrode in the electron-emitting device of FIG.

FIG. 3 is a schematic structural view of a long carbon nanotube structure provided by an embodiment of the present technical solution.

4 is a scanning electron micrograph of a long carbon nanotube tube provided by an embodiment of the present technical solution.

FIG. 5 is a schematic structural diagram of a display device according to an embodiment of the present disclosure.

12‧‧‧Insulation base

14‧‧‧Cathode device

16‧‧‧ Conductive layer

18‧‧‧Electronic emitters

20‧‧‧Insulation support

22‧‧‧Gate

Claims (18)

An electron emission device includes a cathode device and a gate, the gate is spaced apart from the cathode device and electrically insulated from the cathode device, and the improvement is that the gate is a carbon nanotube layer. The carbon nanotube layer includes a plurality of long carbon nanotube structures. The electron-emitting device of claim 1, wherein the carbon nanotube layer comprises a plurality of uniformly distributed gate holes. The electron-emitting device according to claim 2, wherein the gate hole has a pore diameter of 1 μm to 1 cm. The electron-emitting device according to claim 1, wherein the cathode device is a cold cathode device or a hot cathode device. The electron-emitting device of claim 1, wherein the carbon nanotube layer has a thickness of from 2 μm to 400 μm. The electron-emitting device according to claim 1, wherein the plurality of carbon nanotube long-line structures of the carbon nanotube layer are arranged in parallel in the first direction and the second direction, respectively. The electron-emitting device of claim 6, wherein an angle α, 0° ≦ α ≦ 90° is formed between the first direction and the second direction. The electron-emitting device of claim 1, wherein the carbon nanotube long-line structure has a diameter of from 1 μm to 200 μm. The electron emission device of claim 1, wherein the carbon nanotube long-line structure comprises at least one nano carbon tube long line. The electron-emitting device of claim 9, wherein the carbon nanotube long wire has a diameter of from 1 μm to 100 μm. The electron-emitting device according to claim 9, wherein the carbon nanotube long-line is a bundle structure consisting of a plurality of carbon nanotubes arranged in a preferred orientation, or a plurality of end-to-end A twisted wire structure consisting of spirally arranged carbon nanotubes. The electron emission device of claim 11, wherein the carbon nanotube comprises a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube or a mixture of any combination thereof. . A display device comprising: a cathode device; an anode device disposed opposite to the cathode device; a gate disposed between the cathode device and the anode device, and the cathode device Intersected with the anode device, wherein the gate comprises a carbon nanotube layer, and the carbon nanotube layer comprises a plurality of carbon nanotube long-line structures. The display device of claim 13, wherein the carbon nanotube layer comprises a plurality of uniformly distributed gate holes. The display device according to claim 14, wherein the gate hole has a pore diameter of 1 μm to 1 cm. The display device of claim 13, wherein the carbon nanotube layer has a thickness of from 2 μm to 400 μm. The display device of claim 13, wherein the plurality of carbon nanotube long-line structures of the carbon nanotube layer are arranged in parallel along the second direction in the first direction. The display device according to claim 17, wherein an angle α, 0° ≦ α ≦ 90° is formed between the first direction and the second direction.