CN1267964C - Carbon nano tube field emission light-emitting tube and its preparing method - Google Patents

Abstract

The invention discloses a carbon nanotube field emission luminous tube and a preparation method thereof. The method can be made into a multi-color tube or a full-color tube sealed in a cavity. The carbon nanotubes prepared on the metal wire or metal tip are used as the cathode, and the transparent conductive film prepared on the inner wall of the glass tube is used as the anode. The cathode is fixed by an elastic metal hook, and the cathode lead is drawn at the fixed place; the desired position on the anode conductive film Apply phosphor film. The preparation process includes: preparation of cathode, preparation of anode, fixing of elastic metal hooks and lead wire of silver paste, and finally vacuumizing and packaging the cavity of the glass tube with anode and cathode. The invention utilizes the excellent emission characteristics of carbon nanotubes and the characteristics of small radius and high emission efficiency of metal wires to improve the luminous efficiency; using elastic metal hooks to fix the metal wires can well release thermal expansion and contraction caused by temperature changes in the working process , keep the anode and cathode in parallel, increasing the stability and service life of the luminescent tube.

Description

Carbon nanotube field emission luminescent tube and its preparation method

Technical field

The invention belongs to the technical field of luminescence and display, and relates to a field cooling emission luminescent tube, in particular to a carbon nanotube field emission luminescent tube and a preparation method thereof.

Background technique

The field emission luminous tube is a light-emitting device, and its luminous wavelength is determined by phosphor powder, so it can be composed of red, green, and blue three-color tubes together to form a full-color luminous tube or multiple LEDs by applying different voltages or different pulses. The combination of three-color tubes can be used as a large-screen full-color display panel, and single-color tubes can also be used alone. Compared with ordinary light-emitting diodes, it is simple to manufacture, and has low power consumption, high brightness and long life. It can improve the brightness and resolution of the display, and can be used for large-screen display, indoor and outdoor billboards, traffic lights, and indicator lights of electronic instrument automation systems.

At present, carbon nanotube field emission light-emitting tubes have not been reported. Most of the general light-emitting diode (LED) devices are compound semiconductor P-N diodes. energy band mechanism. Its manufacturing process and structure are complicated, and its luminous brightness is low.

Contents of the invention

For above-mentioned phenomenon or deficiency, the object of the present invention is to provide a kind of carbon nanotube field emission luminescent tube and preparation method thereof, the present invention avoids the complex process of making compound semiconductor diode P-N junction, simple in structure, low in cost, and can Improve the emission efficiency, reduce power consumption, and prolong the service life of the luminescent tube.

The technical solution for realizing the above-mentioned carbon nanotube field emission luminescent tube invention is: the carbon nanotube field emission luminous tube includes a glass cavity; it is characterized in that a transparent conductive film is prepared on the inner wall of the glass cavity Anode: At least one metal wire or at least one metal tip fixed on the terminal post by spot welding is arranged in the glass cavity, and the carbon nanotube prepared on the metal wire or the metal tip constitutes the cathode. When the cathode is the carbon nanotube prepared by the metal wire At the same time, the elastic metal hooks fixed on the inner wall of the glass cavity are tightened and fixed at both ends, and the cathode lead is drawn at the fixed place; the corresponding anode conductive film is also coated with a phosphor film, and a metal wire or a spot welding is fixed on the wiring. The metal tips on the pillars correspond to a phosphor coating film of one color; finally, the glass cavity with the anode and cathode is vacuum-packed.

The carbon nanotube field emission luminescent tube of the present invention can be prepared into a monochrome tube, and can also be prepared into a multicolor tube. The cathode of the multicolor carbon nanotube field emission luminescent tube can be made of carbon prepared on several metal wires or metal tips. Composed of nanotubes, several colors of phosphors can be coated in different corresponding areas to increase display resolution.

The carbon nanotube field emission luminescent tube of the present invention can seal three metal wire cathodes prepared with carbon nanotubes in a glass vacuum chamber, and the anode is coated with red, green and blue three-color fluorescent powder, and can share one anode, or can Each is independent, and the three cathodes are independent, so that a field emission light-emitting tube can form a full-color pixel by applying different voltages or different pulses;

The metal wire can be tungsten wire, iron wire, molybdenum wire, nickel wire, etc., and the metal wire is fixed with an elastic metal hook; it can release thermal expansion and contraction caused by temperature changes in the working process, and keep the cathode and anode parallel.

The elastic metal hook is made of elastic metal, and is sintered with low glass powder on the position where the two ends of the conductive film are photoetched in the glass cavity or spot welded on the terminal post sealed with the glass plate.

The shape of the glass cavity can be flat or circular.

Realize the preparation method of above-mentioned carbon nanotube field emission luminous tube, it is characterized in that: comprise the following steps:

1) Cathode preparation

Clean the metal wire or spot weld the metal tip fixed on the terminal, and prepare carbon nanotubes on the wire or metal tip as the cathode by pyrolysis or chemical vapor deposition or coating process;

2) Anode preparation

Prepare a transparent conductive film on the glass plate or the inner wall of the tube, remove the part that does not need the transparent conductive film according to the needs of the lead wire and assembly, and coat the phosphor film on the required position;

3) A metal wire or a metal tip spot-welded and fixed on the terminal, each corresponding to a phosphor coating film of one color;

4) Fix at least one cathode on the inner wall of the glass cavity. When the cathode is a carbon nanotube prepared by a metal wire, prepare a metal elastic hook and fix it at a corresponding position to tighten and fix the wire so that the anode and cathode stay parallel,

5) Lead the cathode lead at the fixed place; finally vacuumize the cavity containing the anode and cathode.

Compared with the prior art, the present invention has the following characteristics:

(1) The present invention cleverly combines the excellent field emission characteristics of carbon nanotubes and metal wires (such as tungsten wires) or metal tips with a very small radius of curvature, and prepares carbon nanometers with excellent emission characteristics on the metal wires or even on the metal wire tips. tube, greatly improving the luminous efficiency.

(2) Fixing the metal wire with an elastic metal hook can well release the thermal expansion and contraction caused by temperature changes during the working process, so that the cathode and anode are kept parallel, thereby increasing the stability and service life of the luminous tube.

(3) Seal three metal wire cathodes growing carbon nanotubes in the glass cavity, and the anodes are coated with red, green, and blue three-color phosphors. Such a light-emitting tube can form a full-color pixel by applying different voltages or different pulses. Dots or multiple three-color tubes are combined as a large-screen full-color display panel. The cathode of the multi-color carbon nanotube field emission light-emitting tube can be several metal wires or metal tips prepared with carbon nanotubes, which can be used in different areas. Apply several colors of phosphor to increase the brightness and resolution of the display.

Description of drawings

Fig. 1 is the structural diagram of carbon nanotube field emission luminescent tube of the present invention and is also the sectional view of embodiment 1;

Fig. 2 is a cross-sectional view (a) and a top view (b) of Embodiment 2 of the carbon nanotube field emission luminescent tube of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and the embodiments completed by the inventors according to the above-mentioned technical solutions.

Referring to Fig. 1, 2, carbon nanotube field emission luminous tube of the present invention comprises a glass chamber 4, is prepared with transparent conductive film 5 to form anode on the glass chamber 4 inner wall; The metal wire 3 or at least one spot welding is fixed on the metal tip on the terminal, and the carbon nanotube 2 is prepared on the metal wire 3 or the metal tip to form the cathode. The inner wall of the body 4 is tightly fixed by the elastic metal hooks 1 at both ends, and the cathode lead wire is drawn at the elastic metal hook 1 with low glass powder sintering at the same time; the phosphor film 6 is also coated on the corresponding anode conductive film 5, and finally the The chamber containing the anode and cathode is vacuum-packed.

The cathode of the light-emitting tube of the present invention is carbon nanotubes, and the carbon nanotubes are prepared on the metal wires, and the metal wires are tightened and fixed by elastic metal hooks, and the elastic metal hooks are fixed in the glass cavity near the two ends where the transparent conductive film is removed. , lead cathode leads by burning silver paste; transparent conductive film is prepared as anode on the glass cavity, remove the part that does not need conductive film according to lead and assembly requirements, and apply phosphor powder on the required position.

The present invention is carried out by following preparation method:

(1) Cathode preparation: carbon nanotubes are prepared on metal wires or metal tips fixed on the terminals by spot welding, and purified after taking them out.

The carbon nanotubes used in the method can be obtained by pyrolysis method, CVD method, coating method and the like.

(2) Anode preparation: Prepare a transparent conductive film on the inner wall of the glass cavity, remove the part that does not need the conductive film according to the lead wire and assembly requirements, and apply phosphor powder on the required position.

(3) Prepare metal elastic hooks, and sinter them with low glass powder in the glass cavity to photoetch off the positions near both ends of the conductive film. Or spot-weld the metal elastic hook on the binding post sealed with the glass plate.

(4) Finally, the cavity containing the anode and the cathode is vacuum-packed.

The working principle of the carbon nanotube field emission luminescent tube of the present invention is: the cathode of the field emission luminescent tube is grounded, and the positive voltage is applied to the anode. When the voltage is added to a certain value, the electric field at the tip of the emitter is strong enough to make the tip of the emitter When the surface barrier becomes lower and narrower, electrons are emitted through the surface barrier, and are accelerated by the electric field to hit the phosphor to stimulate the phosphor to emit light. Therefore, the key to improving field emission efficiency is to prepare emitter tips with a very small radius of curvature. The present invention combines the excellent field emission characteristics of carbon nanotubes with very small metal wires (such as tungsten wires) or metal tips with a radius of curvature. Carbon nanotubes are prepared on the wire or metal tip, which greatly improves the luminous efficiency; in addition, the use of elastic metal hooks to fix the metal wire can well release the thermal expansion and contraction of the metal wire caused by temperature changes during the working process, so that the anode and cathode remain parallel , thereby increasing the stability and service life of the luminous tube.

The carbon nanotube field emission light-emitting tube of the present invention has high brightness, and the emitted light waves are determined by phosphor powder, so red, green, and blue three-color tubes can be combined together or a combination of multiple three-color tubes can be used as a large-screen full-color display panel . Compared with various display pixels and general light-emitting diodes currently used, it has low power consumption, high brightness, long service life and low production cost.

The following are examples given by the inventors, but the present invention is not limited to the examples.

Embodiment 1: A monochromatic circular luminous tube with a structure of molybdenum metal elastic hooks fixing tungsten wires

Its structure is the same as the above-mentioned technical scheme. Its preparation method is:

(1) Cathode preparation: clean the tungsten wire, grow or coat carbon nanotubes on the tungsten wire by pyrolysis or CVD, and purify it after taking it out.

(2) Anode preparation: Dilute the mixed solution of (C ₇ H ₁₅ COO) ₃ In and C ₇ H ₁₅ COO) ₃ Sn with benzene, wherein Sn/In is prepared at a ratio of 10%, and then clean the glass tube and block one end. Pour the mixture of (C ₇ H ₁₅ COO) ₃ In and C ₇ H ₁₅ COO) ₃ Sn into a glass tube to immerse the inner wall of the glass tube for a few minutes, then pour out the mixture, and after heat treatment, slowly dry it. A uniform, hard and transparent ITO conductive film can be formed (or prepared by other processes), and phosphor powder can be coated on the ITO after photolithography according to the wiring and assembly requirements. Of course, the mixed solution for preparing the ITO film can be SnCl ₄ +H ₂ O+InO ₂ solution.

(3) Prepare molybdenum metal elastic hooks, which are sintered with low glass powder in the glass tube to photoetch off the positions near the two ends of the ITO. At the same time, the silver paste is fired to lead the cathode; after sintering, the tungsten wire is fixed.

This method not only releases thermal expansion and contraction caused by temperature changes during the working process of the tungsten wire, but also keeps the cathode and anode parallel, thereby increasing the stability and service life of the luminous tube.

(4) Finally, the cavity containing the anode and the cathode is vacuum-packed.

Embodiment 2: A three-color flat-plate luminous tube with a structure of molybdenum metal elastic hooks to fix tungsten wires

(1) Cathode preparation: clean several tungsten wires, grow or coat carbon nanotubes on the tungsten wires by pyrolysis or CVD, and purify them after taking them out.

(2) Anode preparation: Dilute the mixture of (C ₇ H ₁₅ COO) ₃ In and C ₇ H ₁₅ COO) ₃ Sn with benzene, wherein Sn/In is prepared in a ratio of 10%, and then clean the flat glass, and the (C ₇ Pour the mixed solution of H ₁₅ COO) ₃ In and C ₇ H ₁₅ COO) ₃ Sn on the glass plate and soak the glass plate for a few minutes, pour off the mixed solution, then heat-treat and dry slowly to form a uniform hard The transparent ITO conductive film (or prepared by other processes) is tailored according to the size of the device, and three phosphor films of red, green and blue are coated on the ITO after photolithography according to the needs of leads and assembly. Of course, the mixed solution for preparing the ITO conductive film can be a SnCl ₄ +H ₂ O+InO ₂ solution.

(3) Prepare six molybdenum metal elastic hooks, sinter them with low glass powder on the glass plate to photoetch off the positions near the two ends of the ITO, and burn the silver paste to lead the cathode at the same time; fix three tungsten wires after sintering.

(4) Finally, the casing with the anode and cathode glass and special air holes is sintered with low glass powder to form a cavity, and then vacuum-packed.

Embodiment 3: Three-color light-emitting tube with cylindrical structure and fixed tungsten metal tip by spot welding of terminal

(1) Cathode preparation: Clean the tips of several tungsten wires, grow or coat carbon nanotubes on the tungsten wires by pyrolysis or CVD, and purify them after taking them out.

(2) Anode preparation: Dilute the mixed solution of (C ₇ H ₁₅ COO) ₃ In and C ₇ H ₁₅ COO) ₃ Sn with benzene, wherein Sn/In is prepared in a ratio of 10%, and then clean the short glass tube sealed at one end, Pour the mixture of (C ₇ H ₁₅ COO) ₃ In and C ₇ H ₁₅ COO) ₃ Sn into a glass tube and dip for a few minutes, pour off the mixture, then heat-treat and dry slowly to form a uniform Hard and transparent ITO conductive film (or prepared by other processes), after photolithography according to lead and assembly requirements, red, green and blue three-color phosphor films are respectively coated on ITO. Of course, the mixed solution for preparing the ITO conductive film can be a SnCl ₄ +H ₂ O+InO ₂ solution.

(3) Prepare a glass plate according to the inner diameter of the above-mentioned glass tube, lead three cathodes through the glass plate and fix the tungsten wire tip by spot welding on it, and then leave a suction hole.

(4) Finally, the glass plate equipped with the cathode and the glass tube for preparing the ITO anode are sintered into a cavity with low glass powder, and vacuum-packed. The vacuum-pumped packaging process is similar to that of a light bulb.

Of course, many examples can be given according to the technical solutions disclosed above, which are not exhaustive here, as long as they are within the scope of rights required by the present invention, the present invention can be realized.

Claims (6)

1. A carbon nanotube field emission luminescent tube, comprising a glass cavity (4); It is characterized in that, on the inwall of the glass cavity (4), the anode that is prepared with transparent conductive film (5) is formed; Glass cavity At least one metal wire (3) or at least one metal tip fixed on the terminal post by spot welding is arranged in the body (4), and the carbon nanotube (2) prepared on the metal wire (3) or the metal tip constitutes the cathode. When the cathode is a carbon nanotube (2) prepared by a metal wire (3), it is tightened and fixed by elastic metal hooks (1) fixed on the inner wall of the glass chamber (4) at both ends, and the cathode lead is drawn at the fixed place; the corresponding anode The conductive film (5) is also coated with a phosphor film (6), and a metal wire (3) or a metal tip fixed on the terminal post by spot welding corresponds to a phosphor film (6) of one color. ; Finally, the glass cavity containing the anode and the cathode is vacuum-packed. 2. carbon nanotube field emission luminescent tube as claimed in claim 1, is characterized in that, several cathodes that are prepared with carbon nanotube (2) are arranged in described glass chamber (4), in corresponding different The fluorescent powder (6) of several colors is coated on the area; Can make multi-color light-emitting tube. 3. carbon nanotube field emission luminescent tube as claimed in claim 1, is characterized in that, the metal wire (3) of three growing carbon nanotubes (2) is sealed in described glass vacuum cavity (4) as cathode, The anode formed by the transparent conductive film (5) is coated with red, green and blue three-color phosphors (6), and the three cathodes can share one anode, or make the three cathodes independent to form a full-color pixel field emit glow tubes. 4. The carbon nanotube field emission luminescent tube as claimed in claim 1, characterized in that, the metal wire (3) is one of tungsten wire, iron wire, molybdenum wire, nickel wire, and the elastic metal hook (1) Tighten and fix so that it is parallel to the anode. 5. The carbon nanotube field emission luminescent tube as claimed in claim 1, characterized in that, said elastic metal hook (1) is made of elastic metal, sintered in glass tube (4) with low glass powder Carve off the positions of the two ends of the conductive film (5) or spot weld it on the binding post sealed with the glass plate. 6. A preparation method that realizes the carbon nanotube field emission luminescent tube claimed in claim 1, is characterized in that, comprises the following steps: 1) Cathode preparation Clean the metal wire or spot weld the metal tip fixed on the terminal, and prepare carbon nanotubes on the wire or metal tip as the cathode by pyrolysis or chemical vapor deposition or coating process; 2) Anode preparation Prepare a transparent conductive film on the glass plate or the inner wall of the tube, remove the part that does not need the transparent conductive film according to the needs of the lead wire and assembly, and coat the phosphor film on the required position; 3) A metal wire or a metal tip spot-welded and fixed on the terminal, each corresponding to a phosphor coating film of one color; 4) Fix at least one cathode on the inner wall of the glass cavity. When the cathode is a carbon nanotube prepared by a metal wire, prepare a metal elastic hook and fix it at a corresponding position to tighten and fix the wire so that the anode and cathode stay parallel, 5) Lead the cathode lead at the fixed place; finally vacuumize the cavity containing the anode and cathode.

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