Abstract: An automatic transfer switch includes a first conduction bar selectively coupled with a first power source and a load conduction bar; a second conduction bar selectively coupled with a second power source and the load conduction bar; a first blade assembly electrically coupled to the first conduction bar; and a second blade assembly electrically coupled to the second conduction bar. The first blade assembly is electrically coupled to a first source conduction bar in a closed position, and a first electromagnetic force induced by a first current flowing through the first blade assembly and the first conduction bar repulses the first blade assembly. The second blade assembly is electrically coupled to a second source conduction bar in a closed position, and a second electromagnetic force induced by a second current flowing through the second blade assembly and the second conduction bar repulses the second blade assembly.

Abstract: A circuit that increases input voltage to higher output voltage connected to a variable frequency drive in an appliance. Several switching arrangements, timing, and safety mechanisms are in place to assist. When the circuit experiences high draw, high voltage output values of circuit decrease over time, but different aspects of the circuit can be constructed so that the amount of time required at a higher voltage does not exceed the amount of time in which the high voltage output is provided.

Abstract: The present invention relates to a sputtering target comprising Ni, W and, optionally, one or more further metal(s) X selected from the group of the refractory metals, Sn, Al and Si, which has a normalized peak intensity ratio PIR=INi/IW·(AW+Ax)/ANi of 0.40 or greater, wherein INi is the intensity of the (111) peak of Ni, IW is the intensity of the (110) peak of W, Aw is the fraction of W in the target in atom %, Ax is the total fraction of the one or more further metals selected from the group of the refractory metals, Sn, Al and Si in the target in atom %, ANi is the fraction of Ni in the target in atom %, and wherein the intensities of the peaks are determined by X-ray powder diffraction using Cu-Kalpha radiation.

Abstract: A structure which is resistant to corrosion at high temperatures comprises a layer of ruthenium and/or ruthenium alloy and a layer of a refractory metal having a high strength at high temperatures, such as rhenium. Further, the structure may include a layer of ceramic such as zirconia or hafnia on the exposed face of the ruthenium layer. Alternative embodiments of the present invention include a catalyst formed from a low strength support structure with a first metal layer and a second ruthenium catalytic layer on top of the first metal layer. Another alternative embodiment of the present invention includes the formation of high purity ruthenium electrodes that are resistant to corrosion at high temperatures.

Abstract: A semiconductor device includes a semiconductor substrate, a gate structure, and source/drain regions. The gate structure comprises an yttrium oxide layer over the semiconductor substrate, an aluminum oxide layer over the yttrium oxide layer, and a gate electrode on the aluminum oxide layer. The source/drain regions are on the semiconductor substrate and on opposite sides of the gate structure.

Abstract: The present invention discloses a cylindrical IFD filter, comprising a dust collecting module and a field power module interval arranged inside the channel of the dust collecting module, a plurality of field power module units are symmetrically and vertically spaced arranged on the side wall of the field power module; a plurality of layers of the dust collecting module channels which are stacked vertically are pass-through arranged on the dust collecting module, and each barrier wall between the vertical adjacent dust collecting module channels is alternately disposed as a pair of positive plate and negative plate, each barrier wall between the vertical adjacent dust collecting module channels comprises polar plate electrode and a polar plate coating coated on the upper and bottom walls of the polar plate electrode; and each barrier wall between the lateral adjacent dust collecting module channels adopts same coating material as the polar plate coating.

Abstract: Disclosed is an X-ray tube for improving electron focusing, which allows thermoelectrons emitted from a filament to efficiently reach a target of an X-ray irradiation window. To achieve this, the X-ray tube includes: a thermionic emitter configured to emit thermoelectrons by application of a negative high voltage; a focusing tube configured to focus the thermoelectrons emitted from the thermionic emitter; an X-ray irradiation window configured to irradiate X-rays outside by the thermoelectrons bombarded on a target distributed on the X-ray irradiation window, to generate the X-rays after the thermoelectrons pass through the focusing tube; a tube part including both the thermionic emitter and the focusing tube; and a housing surrounding the tube part, wherein the focusing tube and the housing are configured to have a same potential such that movement directions of the thermoelectrons are directed to the X-ray irradiation window.

Abstract: A light emitting diode includes a first electrode and a second electrode facing the first electrode. The light emitting diode further includes an emitting material layer (EML) disposed between the first electrode and the second electrode, and an electron transport layer (ETL) adjacent the EML. The ETL includes a plurality of first inorganic particles having a first average particle size, and a plurality of second inorganic particles having a second average particle size greater than the first average particle size. The plurality of first inorganic particles may also have a first energy bandgap, and a plurality of second inorganic particles may also have a second energy bandgap smaller than the first energy bandgap.

Abstract: A method for making carrier for use in single molecule detection is related. The method includes following steps: firstly, placing a middle layer on a substrate; secondly, providing a carbon nanotube composite structure, wherein the carbon nanotube composite structure includes a carbon nanotube structure and a protective layer coated on the carbon nanotube structure, the carbon nanotube structure includes a plurality of carbon nanotubes intersected with each other and defines a plurality of openings; thirdly, placing the carbon nanotube composite structure on a surface of the middle layer, wherein parts of the surface are exposed through the plurality of openings; fourthly, forming the patterned bulge by dry etching the middle layer using the carbon nanotube composite structure as a mask, wherein the patterned bulge includes a plurality of strip-shaped bulges intersected with each other; depositing the metal layer on the patterned bulge.

Abstract: The invention provides enrichment platform devices for size-based capture of particles in solution. The enrichment platform device is useful for label-free capture of any particle. The invention relates to enrichment platform devices using nanowires and vertically aligned carbon nanotubes. The invention provides methods for making the enrichment platform devices. The invention provides methods for using the enrichment platform devices for filtering particles, capturing particles, concentrating particles, and releasing viable particles.

Abstract: The present disclosure provides a method of manufacturing a carbon nanotube electron emitter, including: forming a carbon nanotube film; performing densification by dipping the carbon nanotube film in a solvent; cutting an area of the carbon nanotube film into a pointed shape or a line shape; and fixing the cutting area of the carbon nanotube film arranged between at least two metal members to face upwards with lateral pressure.

Abstract: A thermal interface material and method of making the same includes growing a carbon nanotube array on a first substrate and brazing the distal ends of the carbon nanotube array to a second substrate using a braze material. In at least one embodiment, the braze material includes active elements. The method further includes performing the brazing process in an inert or vacuum atmosphere.

Abstract: The present disclosure relates to a manufacturing method for an electron emitting device using a graphite adhesive material. A method of preparing paste for forming a cathode of an electron emitting device includes: mixing and dispersing a nanomaterial for electron emission and a graphite filler in a solvent; drying a mixed solution in which the nanomaterial and the graphite filler are mixed; and preparing paste by mixing a graphite binder with the dried mixture.

Abstract: In an example, a method to form a low work function insert includes preparing a mixture that includes a first powder that contains barium, a second powder that contains calcium, a third powder that contains at least one of aluminum, samarium, or magnesium, and a fourth powder that contains a refractory metal. The method may also include heating the mixture, contained in a crucible, in a furnace. Oxygen concentration in the furnace may be maintained at a low partial pressure during heating of the mixture in the furnace. The low work function of the insert allows electrons to be readily extracted from its surface.

Abstract: A method for transferring a carbon nanotube array is disclosed. The carbon nanotube array has an ability to have a carbon nanotube structure drawn therefrom. The carbon nanotube array is transferred from a growing substrate to a substitute substrate, meanwhile the carbon nanotube array is still having the ability to have a carbon nanotube structure drawn from the substitute substrate. The substitute substrate is placed on the top surface of the carbon nanotube array. An adhesive layer is sandwiched between the substitute substrate and the carbon nanotube array. The substitute substrate is separated from the growing substrate, thereby separating the bottom surface of the carbon nanotube array from the growing substrate. A method for making a carbon nanotube structure is also disclosed.

Abstract: The disclosed subject matter includes devices and methods relating to vacuums and vacuum assemblies. In some aspects, methods and devices relate to a vacuum assembly including a body defining an evacuated vacuum chamber, a conduit in the body extending between the vacuum chamber and an exterior of the body, a plug at least partially occluding the conduit, and a seal between the plug and the body that seals the vacuum chamber from the exterior of the body.

Abstract: An assembly for nucleic acid sequencing by tunnel current analysis has at least two electrically conductive particles having a diameter from 1 nm to 100 nm and at least two electrically insulating particles having a diameter from 1 nm to 100 nm. The particles are in particular spherically shaped. The assembly also has at least two first electrodes for contacting the electrically conductive particles and a substrate on which the first electrodes and the particles are arranged. The four particles are arranged substantially in a planar square. The conductive particles lie diagonally opposite each other, and the insulating particles lie diagonally opposite each other. The gap between the four particles is used as a solid-state nanopore for nucleic acid sequencing.

Abstract: A fluid cooled lamp includes: a heat conductive pipe has multiple heat conductive surfaces and a hollow channel; multiple illumination modules arranged at each heat conductive surface; a junction assembly for inlet and outlet of fluid including an inlet joint and an outlet joint, the inlet joint and the outlet joint are respectively communicated with both ends of the hollow channel; a flow guiding inner tube communicated with inlet joint and located in the hollow channel, multiple spray holes are disposed in the flow guiding inner tube, the fluid is sprayed from each spray hole and impacts an inner wall of the heat conductive pipe to remove heat.

Abstract: A technique of measuring energy of electrons excited by exposing a semiconductor material to solar ray is proposed. A surface layer having a negative electron affinity is formed on the surface of a semiconductor material. The semiconductor material is placed in a vacuum environment and exposed to solar ray. Photoelectrons emitted from the surface layer having the negative electron affinity are guided to an energy analyzer, and the energy of electrons excited by the solar ray is measured. Since the surface layer having the negative electron affinity is used, the photoelectrons are obtained from the electrons excited by the solar ray, and thereby energy measurement becomes possible.

Abstract: A substrate is for use in manufacturing a display device. The substrate includes a first area that corresponds to pixel positions. The substrate further includes a second area adjacent to the first area. The substrate further includes a first mark disposed in the second area, wherein a first virtual line corresponds to the first mark. The substrate further includes a second mark disposed in the second area and spaced from the first mark, wherein a second virtual line corresponds to the second mark and intersects the first virtual line at a virtual reference point. The substrate further includes an indicator disposed in the second area, spaced from the first mark and the second mark, and corresponding to an opening of a mask, wherein a positional relation between the virtual reference point and a point of the indicator represents a positional relation between the substrate and the mask.

Abstract: A material for organic electroluminescence element, including: a phosphorescent compound; and a discotic liquid-crystalline host compound, wherein the phosphorescent compound has an aspect ratio of molecule core diameter to molecule core thickness (molecule core diameter/molecule core thickness) of at least 3, and wherein a size ratio of the molecular radius of the phosphorescent compound to the molecular radius of the discotic liquid-crystalline host compound (molecular radius of the phosphorescent compound/molecular radius of the discotic liquid-crystalline host compound) is 0.8 to 1.2.

Abstract: A pulsed neutron generator includes neutron tube and a high voltage power supply. High voltage power supply includes a bulkhead and plurality of electronic components electrically connected between the bulkhead and the target of the neutron tube. A heat pipe is provided in thermal contact with the target and has a housing portion with an exterior surface supporting the plurality of electronic components of the high voltage power supply. Heat pipe includes wick and heat transfer fluid disposed within the housing portion. The wick for recirculates the heat transfer fluid within the housing portion in order to transfer heat away from the target preferably to the bulkhead for dissipation the system housing. Both the wick and heat transfer fluid are preferably realized from materials that have low electrical conductivity. The heat pipe can also be part of other-type particle accelerators, such as x-ray sources and gamma-ray sources.

Abstract: The present technology includes a semiconductor memory device, including a channel layer and interlayer insulation layers surrounding the channel layer. The interlayer insulation layers are stacked with a trench interposed therebetween. A seed pattern is formed on a surface of the trench and a metal layer is formed on the seed pattern in the trench.

Abstract: A dielectric gradient metasurface optical device provides optical wavefront shaping using an ultrathin (less than 100 nm thick) layer of nanoscale geometric Pancharatnam-Berry phase optical elements deposited on a substrate layer. The optical elements are nanobeams composed of high refractive index dielectric material. The nanobeams have uniform size and shape and are arranged with less than 200 nm separations and spatially varying orientations in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The high refractive index dielectric material may be materials compatible with semiconductor electronic fabrication, including silicon, polysilicon, germanium, gallium arsenide, titanium dioxide, or iron oxide.

Abstract: Provided is a conductive film having a high conductivity in which electric resistance is less likely to increase, and a conductive composition for forming the same. The conductive composition includes an elastomer component, a fibrous carbon material having a fiber diameter of less than 30 nm, and a flake-like carbon material having a graphite structure, having an intensity ratio (G/D ratio) of a peak (G band) appearing in the vicinity of 1580 cm?1 to a peak (D band) appearing in the vicinity of 1330 cm?1 of Raman spectrum of not less than 1.8, and having a maximum length of not less than 150 nm and a thickness of not more than 100 nm. The conductive film is formed from the conductive composition.

Abstract: The disclosure relates to a method for making field emission cathode. A microchannel plate is provided. The microchannel plate includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The plurality of holes are filled with a carbon nanotube slurry. The carbon nanotube slurry is adhered on inner walls of the plurality of holes. The carbon nanotube slurry in the plurality of holes is solidified.

Abstract: A display includes: a laminated wiring with a conductive film arranged on a foundation layer, and a transparent film and a translucent film arranged on the conductive film; a wiring terminal part arranged at an edge portion of the laminated wiring and having the same laminated structure as that of the laminated wiring; and an insulating film that covers the laminated wiring and the wiring terminal part.

Abstract: An apparatus for displaying a scene with light in a range of infrared wavelengths, includes: an array of elements configured to emit light in a range of infrared wavelengths, each element having one or more nanotubes; a stimulator configured to apply a stimulus to each element in the array in order for each element to emit light in the range of infrared wavelengths; and a processor configured to send a signal to the stimulator in order to apply the stimulus to one or more selected elements in the array to display the scene.

Abstract: A method for making carbon nanotube field emitter includes providing a carbon nanotube array formed on a surface of a substrate. A plurality of carbon nanotubes of the carbon nanotube array is selected and pulled out a carbon nanotube film by a drawing tool, wherein the carbon nanotube film includes a plurality of carbon nanotubes oriented along a fixed direction. The carbon nanotube film is cut to a plurality of uniform carbon nanotube sub-films along the fixed direction. The plurality of carbon nanotube sub-films is treated to a plurality of carbon nanotube yarns. The plurality of carbon nanotube yarns is fixed on a surface of a conductive base, and cutting off the plurality of carbon nanotube yarns by a laser beam, to form a carbon nanotube field emitter.

Abstract: Provided are methods of aging an x-ray generator having carbon nanotube electron emitters. The method of aging an x-ray generator that includes a cathode, a gate electrode, and an anode, includes applying a desired, or alternatively predetermined anode voltage to the anode, and applying a direct current pulse voltage to the gate electrodes to emit electrons from electron emitters. The method further includes maintaining an anode current formed by electrons generated from the electron emitters constant.

Abstract: Provided is a manufacturing method of a CNT emitter with density controlled CNT, comprising: (i) fabricating a CNT paste by dispersing a carbon nanotube (CNT) powder, two kinds or more of inorganic fillers which have a lower melting temperature than the CNT and different oxidation degrees of the CNT, and an organic binder in a solvent; (ii) coating the CNT paste on an electrode formed above a substrate; (iii) sintering the substrate coated with the CNT paste to selectively oxidize the CNT around one kind of inorganic filler among two kinds or more of the inorganic fillers; and (iv) treating the surface of the CNT paste so that the surface of the CNT paste is activated.

Abstract: A display device includes a laminated wiring formed of a low-resistance conductive film, and a low-reflection film mainly containing Al and functioning as an antireflective film which are sequentially arranged on a transparent substrate, a wiring terminal part provided at an end part of the laminated wiring and has the same laminated structure as that of the laminated wiring, and an insulating film for covering the laminated wiring and the wiring terminal part, in which the insulating film side serves as a display surface side, the wiring terminal part has a first opening part penetrating the insulating film and the low-reflection film and reaching the low-resistance conductive film, and an outer peripheral portion of the first opening part has a laminated structure of the low-resistance conductive film, the low-reflection film, and the insulating film, in at least one part.

Abstract: A method for making carbon nanotube slurry is presented. At least one carbon nanotube film is provided, the at least one carbon nanotube film includes a plurality of carbon nanotubes oriented along substantially the same direction. A substrate is provided, and the at least one carbon nanotube film is attached to a surface of the substrate. The at least one carbon nanotube film is cut perpendicular the oriented direction of the carbon nanotubes with a laser to form a carbon nanotube belt. An inorganic binder and an organic carrier is provided, the carbon nanotube belt, the inorganic binder, and the organic carrier are mixed in an organic solvent to form a mixture. The organic solvent is removed.

Abstract: A display device includes a laminated wiring formed of a low-resistance conductive film, and a low-reflection film mainly containing Al and functioning as an antireflective film which are sequentially arranged on a transparent substrate, a wiring terminal part provided at an end part of the laminated wiring and has the same laminated structure as that of the laminated wiring, and an insulating film for covering the laminated wiring and the wiring terminal part, in which the insulating film side serves as a display surface side, the wiring terminal part has a first opening part penetrating the insulating film and the low-reflection film and reaching the low-resistance conductive film, and an outer peripheral portion of the first opening part has a laminated structure of the low-resistance conductive film, the low-reflection film, and the insulating film, in at least one part.

Abstract: An electron emission source includes nano-sized acicular materials and a cracked portion formed in at least one portion of the electron emission source. The acicular materials are exposed between inner walls of the cracked portion. A method for preparing the electron emission source, a field emission device including the electron emission source, and a composition for forming the electron emission source are also provided in the present invention.

Abstract: A field emission device includes a cathode and a carbon nanotube (CNT) gate electrode. The CNT gate electrode which is electrically insulated from the cathode includes a CNT layer and a dielectric layer. The CNT layer which has a surface includes a number of micropores. The dielectric layer is coated on the surface of the CNT layer and an inner wall of each of the micropores.

Abstract: A thermionic emission assembly includes a Wehnelt cap that has a cap beam aperture and a cavity within which a cathode is supported. Electrical energy applied to the cathode causes it to reach a sufficiently high temperature to emit a beam of electrons that propagate through the cap beam aperture. An anode having an anode beam aperture is positioned in spatial alignment with the cap beam aperture to receive the electrons. The anode accelerates the electrons and directs them through the anode beam aperture for incidence on a target specimen. A ceramic base forms a combined interface that electrically and thermally separates the Wehnelt cap and the anode. The thermal isolation of the Wehnelt cap from the anode allows the Wehnelt cap to increase in heat to rapidly reach a stable temperature as the cathode emits the beam of electrons.

Abstract: Wire-suspended thermionic cathodes provide lower power, further reduction in size, better stability and accuracy, and higher loading then conventional art. The cathodes are too small for use with conventional heaters and so are heated from behind by an electron beam or an intense light beam, such as laser light transmitted via optical fiber to the back of the cathode. The cathodes are electrically isolated from the focus electrode, thus allowing beam cutoff and modulation.

Abstract: There is provided an iridium tip including a pyramid structure having one {100} crystal plane as one of a plurality of pyramid surfaces in a sharpened apex portion of a single crystal with <210> orientation. The iridium tip is applied to a gas field ion source or an electron source. The gas field ion source and/or the electron source is applied to a focused ion beam apparatus, an electron microscope, an electron beam applied analysis apparatus, an ion-electron multi-beam apparatus, a scanning probe microscope or a mask repair apparatus.

Abstract: The present invention aims to prevent breakage of a sealing part and an electrode of a high pressure discharge lamp, and provides an electrode 100 used for a discharge lamp and having a rod-shaped part 101, one end of the rod-shaped part 101 to be sealed by a sealing part of an arc tube of the discharge lamp, the other end of the rod-shaped part 101 to be in a discharge space in the arc tube, wherein the rod-shaped part 101 has a rough surface that is composed of a plurality of types of crystal grains each having a different surface condition due to differences in crystal orientation.

Abstract: A carbon nanotube field emitter is disclosed. The carbon nanotube field emitter includes an emission portion and a supporting portion. The emission portion and the supporting portion are configured as one piece to form a roll structure. The emission portion includes a first rolled carbon nanotube layer, which includes a number of carbon nanotubes. The supporting portion includes a rolled composite layer, which includes at least one second rolled carbon nanotube layer and a rolled metal layer stacked with each other. Another carbon nanotube field emitter with a number of separated emission tips on the emission portion is also disclosed.

Abstract: A cold cathode field emission electron source capable of emission at levels comparable to thermal sources is described. Emission in excess of 6 A/cm2 at 7.5 V/?m is demonstrated in a macroscopic emitter array. The emitter is comprised of a monolithic and rigid porous semiconductor nanostructure with uniformly distributed emission sites, and is fabricated through a room temperature process which allows for control of emission properties. These electron sources can be used in a wide range of applications, including microwave electronics and x-ray imaging for medicine and security.

Abstract: The present application relates to a method for making a carbon nanotube field emitter. A carbon nanotube film is drawn from the carbon nanotube array by a drawing tool. The carbon nanotube film includes a triangle region. A portion of the carbon nanotube film closed to the drawing tool is treated into a carbon nanotube wire including a vertex of the triangle region. The triangle region is cut from the carbon nanotube film by a laser beam along a cutting line. A distance between the vertex of the triangle region and the cutting line can be in a range from about 10 microns to about 5 millimeters.

Abstract: A field emission display is also provided. The field emission display includes a plurality of pixel units. Each of the plurality of pixel units includes a first electrode located on the insulating substrate; a plurality of first electron emitters located on and electrically connected to the first electrode; a first phosphor layer located on the first electrode; a second electrode located on the insulating substrate and spaced from the first electrode, wherein the second electrode extends at least partly around the first electrode; a plurality of second electron emitters located on and electrically connected to the second electrode; and a second phosphor layer located on the second electrode.

Abstract: Embodiments of the invention include methods and devices for producing light by injecting electrons from field emission cathode across a gap into nanostructured semiconductor materials, electrons issue from a separate field emitter cathode and are accelerated by a voltage across a gap towards the surface of the nanostructured material that forms part of the anode. At the nanostructure material, the electrons undergo electron-hole (e-h) recombination resulting in electroluminescent (EL) emission. In a preferred embodiment lighting device, a vacuum enclosure houses a field emitter cathode. The vacuum enclosure also houses an anode that is separated by a gap from said cathode and disposed to receive electrons emitted from the cathode. The anode includes semiconductor light emitting nano structures that accept injection of electrons from the cathode and generate photons in response to the injection of electrons.

Abstract: A field emission cathode device includes a substrate and a carbon nanotube structure. The substrate includes a first surface. The carbon nanotube structure defines a contact body and an emission body. The contact body is contacted to the first surface of substrate. The emission body is curved away from the first surface. The carbon nanotube structure includes a number of carbon nanotubes joined end to end from the contact body to the emission body to form a continuous structure.

Abstract: A method for making an emitter is disclosed. A number of carbon nanotubes in parallel with each other are provided. The carbon nanotubes have a number of first ends and a number of second ends opposite to the number of first ends. The first ends are attached on a first electrode and the second ends are attached on a second electrode. The first electrode and the second electrode are spaced from each other. A voltage is supplied between the first electrode and the second electrode to break the carbon nanotubes.

Abstract: A discharge lamp (1) comprising a discharge vessel (4), at least one electrode (22, 24) arranged within the discharge vessel, wherein at least parts of the electrode (22) are provided with a particle composite coating (32) made up of a matrix layer and particles embedded in the matrix layer, wherein the extinction coefficient k of the material for the matrix layer is less than 0.1 in the spectral range between 600 nm and 2 ?m, and wherein the extinction coefficient k of the material for the particles is greater than 0.1 in the spectral range between 600 nm and 2 ?m.

Abstract: Plasma uniformity can be improved. An upper electrode 105 for use in a parallel plate type plasma processing apparatus includes a base 105a made of a dielectric material; and a conductive layer 110 formed on at least a part of a surface of the base 105a facing a lower electrode 210 provided in the plasma processing apparatus. Further, the conductive layer 110 having a dense and sparse pattern such that the dense and sparse pattern at an outer portion of the surface of the base 105a facing the lower electrode 210 is denser than at an inner portion thereof.

Abstract: A vacuum ionization gauge includes a cold cathode, a shield electrode, an anode ring, and a collector. The shield electrode includes a receiving space. The anode ring is located in the receiving space of the shield electrode. The cold cathode includes a field emission unit and a grid electrode corresponding to the field emission unit. The field emission unit includes at least one emitter. Each of the at least one emitter includes a carbon nanotube pipe. The carbon nanotube pipe has a first end, a second end, and a main body connecting to the first end and the second end. The second end has a plurality of carbon nanotube peaks.