137results about How to "Improve field emission performance" patented technology

The invention discloses a carbon nano fiber/carbon nanotube heterogenous nano array capable of being used for a field electronic emitter and a preparation method thereof. The preparation method mainly comprises the following steps: (1) taking a silicon single-crystal chip or a glass sheet or a ceramic chip, and the like as a substrate; (2) utilizing magnetic filtration vacuum vapor arc plasma deposition technology or magnetron sputtering technology to deposit a catalyst film on the substrate; (3) performing high-temperature heat treatment on the catalyst film in an ammonia gas reaction chamber; (4) introducing working mixture taking hydrogen as carrier gas and acetylene as reaction gas at high temperature, and synthesizing a directional carbon nanotube array on the substrate subjected to heat treatment; (5) adopting an energy-carrying ion beam or a plasma to process the carbon nanotube, and forming the carbon nano fiber/carbon nanotube heterogenous nano array; and (6) using the carbon nano fiber/carbon nanotube heterogenous nano array to process the field electronic emitter.

The invention discloses a new method for synthesizing patterned single-crystal tungsten oxide nanowire arrays with a catalyst localization technology. Employing a tungsten film as a source material and a metal nanoparticle film as a catalyst, the method comprises: (a) catalyst film localization synthesis: realizing film patterning through fixation of a ceramic template and a substrate material together or application of the exposure technology in a micromachining process, then enabling localization growth of the catalyst nanoparticle film in a vacuum plating instrument; (b) chemical vapor deposition: in a reaction gas atmosphere and at a temperature of 400-800DEG C, placing a W film into a CVD device for growth of 1-8h, then opening a fixation device or removing a photoresist, thus finally obtaining patterned tungsten oxide nanowire arrays. The preparation method of the invention not only can prepare patterned tungsten oxide nanowire arrays of different growth density, but also has the advantages of low reaction temperature (lower than 500DEG C) and suitability for the growth of low-melting point substrates.

A carbon nitride nanotube array used for field emission device can be directly grown on the substrate. Its diameter is 20-200 nm. Its length is 1-100 microns. Its N content is 0.5-9%. Its initial emissino field is 1.5-5 V/micron.

The invention provides a method for preparing a titanium dioxide nano tip array film for field emission, mainly comprising the following steps of: firstly, performing primary anodic oxidation on a swing-cleaned titanium sheet, and then removing the titanium dioxide nano-tube film attached to the titanium sheet through ultrasound; and next, loading the titanium sheet into the electrode again and performing secondary anodic oxidation, and then taking out the titanium sheet for cleaning through swinging to finally obtain the titanium dioxide nano tip array film. The method provided by the invention realizes the preparation of the titanium dioxide nano tip array film suitable for field emission. Compared with the traditional microelectronic field emission tip array, the method provided by the invention is simple, and preparation parameters are easy to control; and the tip of the array is sharp, which is advantageous for gaining field emission. Furthermore, the titanium dioxide nano tip array film annealed at high temperature previously has lower opening and threshold field intensity; and particularly, the sample annealed at 450 DEG C has the minimum opening and threshold field intensity and is obviously improved in field emission performance.

The invention provides a carbon nanotube composite thin film field emission cathode preparation method. The carbon nanotube composite thin film field emission cathode preparation method includes the following steps that: S1, nanotube/TiC/Ti composite materials are prepared; S2, the nanotube/TiC/Ti composite materials and nano filling particles are mixed according to at the mass ratio of 5:1 to 1:5, and the mixture is added to an organic solvent, and ultrasound is adopted to perform dispersion, and a first slurry can be formed; S3, the first slurry is transplanted on a silver electrode, and a nanotube composite film can be formed; S4, the nanotube composite film is put into a sintering furnace so as to be subjected to vacuum sintering or reducing atmosphere sintering for more than 15 minutes under temperature from 200 DEG C to 600 DEG C; S5, Ti on the surface of the sintered carbon nanotube composite film is corroded and removed through using a corrodent, and a carbon nanotube/TiC emission tip is exposed, and a carbon nanotube composite thin film field emission cathode can be formed. With the carbon nanotube composite thin film field emission cathode prepared by the invention adopted, adhesion and electrical contact between the emitter and the base of a carbon nanotube can be improved, and field emission performance can be improved.

The invention provides a diamond nano needle array composite material and a preparation method and an application thereof. The diamond nano needle array composite material provided by the invention comprises a substrate layer and a diamond nano needle array which is formed on the surface of the substrate layer, wherein a three-dimensional graphene layer grows on the surface of a diamond nano needle in the diamond nano needle array. The preparation method of the diamond nano needle array composite material, disclosed by the invention, comprises the following steps: depositing a diamond film layer on the surface of a base body; etching the diamond film layer into a diamond nano needle array; and enabling the three-dimensional graphene layer to grow on the surface of the diamond nano needle array. The diamond nano needle array composite material disclosed by the invention is excellent in heat-conducting property, high in property field emission property and stability, simple in preparation process, and good in condition controllability, and can be applied to gas sensors, biosensors and electrochemical fields.

The invention relates to a low-cost low-pollution gallium nitride (GaN) nano-wire preparation generation method, and belongs to the field of inorganic compound semiconductor materials. The method provided by the invention comprises the steps that: (1) GaN powder is subjected to gum-doping, grinding, tabletting, and calcining, such that a GaN target is prepared; (2) a washed and bake-dried silicon wafer is deposited for 30-60s by using a SBC-12 small ion sputtering instrument, such that a substrate with a gold film with a thickness of 10-30nm on the surface is obtained; and (3) a plasma-assisted hot-wire chemical vapor deposition method is utilized, wherein an atmospheric pressure is 1500Pa-2500Pa, a substrate temperature is 800-1000 DEG C, a bias current is 100mA-180mA, a flow rate of fed nitrogen is 10-50cm<3>/min, a flow rate of fed hydrogen is 10-50cm<3>/min, and a deposition time is 5-30min. With the method provided by the invention, solid and linear gallium nitride nano-wires can be obtained. The product is straight, neat, ordered, uniform, and linear. Chemical and physical properties of the nano-wires are stable. The preparation process is short, and product growth is fast. Product diameter reaches 40-150nm, and an average single wire length is 10-15mum.

The invention relates to a preparation method of an injector-shaped ZnO nano-structural array for field emission, which is a two-step synthesis method based on an aqueous solution system. The method comprises the following steps: firstly, adopting a electrochemical deposition method to directly grow a ZnO nano-column array on a conductive glass substrate; and secondly, adopting the aqueous solution chemical growing method to perform epitaxial growth of nano-needles on the original end surfaces of the ZnO nano-columns. The injector-shaped ZnO nano-structural array is prepared by the two-step synthesis method, thus the adhesive strength of the ZnO nano-structural array on the conductive substrate can be ensured, the electrical conductivity can be increased, the controllable growth of the pointed nanostructure, which is beneficial for electron emission can be realized and the field emission performance of the array structure can be improved.

The process of preparing carbon nanotube/silicon nest array includes the following steps: setting P-type monocrystalline silicon chip inside a autoclave, and filling solution of 8.00-22.00 mol/l concentration hydrofluoric acid and 0.01-0.50 mol/l ferric nitrate solution to etch at 50-200 deg.c for 10 min to 36 hr to preparing silicon with nanometer pore array as the substrate material; setting the substrate material inside a tubular furnace, heating to 500-1200 deg.c in protective atmosphere, feeding carbon source solution with dissolved organic metal salt along with the carrier gas to in-situ grow carbon nanotube for 1-60 min, and cooling to room temperature under the protection of gas to obtain carbon nanotube/silicon nest array with field emitting and humidity sensing functions. The carbon nanotube/silicon nest array device has the performance as shown, and the preparation process is simple and high in repetition rate.

The preparation method for field emission electron cathode made of quasi-diamond material comprises: with bluster beam current, depositing the high-density nano pinpoint emitter on substrate for high emission current and low emission threshold; in the high-vacuum chamber, impacting and RF magnetic-controlled sputtering with Ar and He gas to prepare nano particle, orienting the beam to the substrate, and changing the beam strength and deposition time to prepare the high-density emitter. The adjustment method for beam current comprises: adjusting the Ar and He gas in target chamber to 101-102sccm and 1:1-5:1 partial pressure ratio, adjusting the final size constituent of the working flow; adjusting the distance between the sputtering target material and the small hole more than 10cm, and adjusting the nano particle and the final emitter size.

The invention provides a preparation method and an application of a hydrogenated titanium dioxide nanotube array film. The preparation method comprises the following steps: cleaning an industrial titanium sheet, and chemically polishing; oxidizing at room temperature through a constant-voltage direct-current anodizing method; and carrying out heat treatment in a vacuum environment in a hydrogen-containing atmosphere, stopping the let-in of hydrogen, and naturally cooling to room temperature in an argon atmosphere to prepare the hydrogenated titanium dioxide nanotube array film. The hydrogenated titanium dioxide nanotube array film can be directly used as a field electron emission cold cathode. The preparation method enables the hydrogenated titanium dioxide nanotube array film having the characteristics of low turn-on field, large emission current density, good field emission stability, high repeatability and the like and directly used as the field electron emission to be prepared; and the preparation method can be used for the industrial production, enables the cold cathode field emitters having low prices to be prepared, and can be well applied in the field electron emission display cathode material field.

The invention discloses a preparation method of a silicon nanowire array with excellent field emission performance and a tip structure, and belongs to the technical field of field emission. The method comprises the following steps: firstly configuring single-layered PS (Polystyrene) spheres densely on a silicon substrate, carrying out reactive ion etching treatment on the PS spheres, adopting an electron beam evaporation method to plate silver, removing the PS spheres, carrying out silver catalytic corrosion to the substrate, and obtaining the silicon nanowire array with larger diameter; adopting a dry-method oxidation treatment to turn the silicon nanowires into the tip structure, further reducing the diameter of the silicon nanowires, and increasing the space between the silicon nanowires. The silicon nanowire array with the tip structure, prepared with the method, is of excellent field emission performance; the threshold voltage of the silicon nanowire array is 1.8 V per microns; the current stability is good; meanwhile, the single crystal performance of the silicon nanowires is good, so that the silicon nanowires can be regularly and densely configured in a large area, and the controllability of the draw ratio is strong. The method is low in cost, high in yield and good in controllability, so as to be applied to production of silicon-substrate field emission electronic devices.

The invention discloses a symmetrical type carbon nanotube cathode ionization gauge. A carbon nanotube array capable of achieving electron field emission at room temperature is taken as a cathode, interferences of the high-temperature thermionic cathode to a heat sensitive, light sensitive and strong magnetic field system are overcome, and a power consumption demand is reduced based on a field emission mechanism. The carbon nanotube array cathode grows on two faces of a substrate, and symmetrical double-electrode arrangement is adopted; and, on the premise that the complexity of a circuit is not changed, the lengths of electron trajectories are effectively prolonged, and improvement of the sensitivity of an ionization gauge in the kind is facilitated. Furthermore, higher-voltage anodes 5 are added between gate electrodes 4 and collecting electrodes 6, so electrons oscillates between the gate electrodes 4 and the collecting electrodes 6, the electron trajectories are also prolonged, and the sensitivity of the ionization gauge is further improved.

The invention discloses a method for preparing a zinc oxide nano-layer structure on a supportless carbon nano-tube film, which is characterized in that zinc oxide is evenly attached to the supportless carbon nano-tube film to form the zinc oxide nano-layer structure through thermal evaporation by using nitrogen as carrier gas, wherein the zinc oxide nano-layer has a needle-like structure; the length thereof is 1mu m; and the particle size of zinc oxide particles is about 100 nanometers. The method improves the field emission characteristic of a carbon tube, improves the field emission performance and increases the field emission current density with lower turn-on electric field and good emission stability; and compared with the prior art, the method has the advantages of simple manufacturing process, low cost and good repeatability, is particularly suitable for large-area manufacture, and can perform kinking and clipping.

A field emission lighting device is disclosed in the present invention. The field emission lighting device includes a cathode, an isolating layer, a plurality of isolating emitter bases, a plurality of niobium emitter tips each formed on a respective emitter base, a light-permeable anode disposed opposite to the cathode, and a fluorescence layer formed on the anode. The isolating layer is formed on the cathode. The isolating emitter bases extend from the isolating layer. The isolating layer and the isolating emitter bases are comprised of diamond like carbon. The isolating emitter bases each include an electrically conductive connecting portion configured for establishing an electrically conductive connection between the emitter tip and the cathode.