TWM376890U - The electron emission device and electromagnetic wave generator of carbon nanotube - Google Patents

Abstract

This creature is providing an electron emission device and Electromagnetic Wave Generator that can achieve a high electron emission efficiency even in case of a small exciting energy. The electron emission device is provided with a carbon nanotube layer 12 formed on a SiC base plate 11 and composed of a plurality of carbon nanotubes oriented in a perpendicular direction to a surface of the SiC base plate 11, a MgO layer 13 formed on the carbon nanotube layer 12 and contacting with the carbon nanotube layer 12, an Ohmic electrode 17 connected with the carbon nanotube layer 12, an electrode 15 arranged to face the MgO layer 13 with a space 14 in-between, and a voltage source 16 to impress a voltage between the Ohmic electrode 17 and the electrode 15.

Description

V. New type of description: [Technical field to which the new type belongs] This month's newsletter relates to an electronic display device and an electromagnetic wave generating device, and more particularly to an electronic radiation device and an electromagnetic wave generating device for making a slave. [Prior Art] In recent years, since the requirements for the display, the electron microscope, the illumination device, and the electric per-skin production device are relatively high, the high efficiency of the genus of the scale device is difficult. For the purpose of high output, the development of an electron emission device using nanocarbon « is prevalent. The carbon nanotube system is able to increase the gas conductivity in the direction along the tube. Ploughing, she (4) knows that the electric side of the electric side rides the metal material of the Lang. Because the tube (4) is off the line, the front end (4) field strength is higher than the flat double. Therefore, by using a carbon nanotube in an electron emission device, it is expected that high electron emission efficiency can be obtained. In addition, since the Taiping ancient 卜 不 不 不 由于 由于 由于 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 石 村 村 村 村 村 村However, in order to achieve the high efficiency of the electronic women, it is oriented to the electronic _ direction, and indeed from the Taifeng. The front end of the Tai 4 shirt will be electronically radiated 'Τ...carbon (4) directional growth technology. It is known that there is a metal secret board that will have the function of a catalyst. When the silk is in the state of high temperature, the nr body is called a gas phase chemical reaction. The raw carbon carbon (4) method or the vacuum and the old high-temperature annealing to remove & fine to produce oriented carbon nanotubes dedicated to the special opening 2 · 15. The use of the 77 The electronic radiation device composed of the four (4) official is shown in FIG. The electron emission device is composed of: an n-type SiC substrate 11; and a carbon nanotube layer 12' which is formed by a high temperature annealing method in the above vacuum, and is composed of a oriented carbon nanotube; The electrode 15; the resistive electrode 17; and the voltage source 16 is applied between the electrode 15 and the resistive electrode 17 on the SiC substrate U. In such an electron emission device, electrons emitted from the surface of the carbon nanotube layer U move to the gap 14. [The subject to be solved by this creation] However, even in the electron emission device W using the oriented carbon nanotube shown in Fig. 8, the read function of the parameter of the radiation scale governing the electron is 4~ High, the probability of electron release of Wei S, must have high excitation energy. Therefore, the electron emission is difficult to achieve high electron emission efficiency. At this time, the technology of electron emission efficiency was reported, and the carbon nanotubes coated with Mg〇 were distributed in the case where the distribution electrons were not completely oriented, so that the technology of the electrons was revealed in Applied Physics Letters. , served 1〇9811〇6 (2〇〇2) However, in the technology s 17 ' § electricity? When the excitation energy of the line is low, the same radiation efficiency of the expected electrons cannot be achieved. Therefore, this technology cannot achieve high electron emission efficiency. [New content] The purpose of this creation is to provide an electronic arsenal, which can achieve high electron emission efficiency even when the excitation energy is small. In order to achieve the object, the electron emission device of the present invention comprises: a carbon nanotube layer formed on a substrate and composed of a plurality of carbon nanotubes oriented in a vertical direction to the surface of the substrate; metal oxide The layer 'is formed on the carbon nanotube layer and is in contact with the aforementioned carbon nanotube layer; the first 'series is connected to the aforementioned carbon nanotube layer; and the second electrode is separated It is disposed between the metal oxide layer and the metal oxide layer. According to such a configuration, (4) the surface of the carbon nanotube layer is gamma-deposited to have a metal oxide layer, and the barrier height at the time when the carbon nanotubes are electrically removed from the surface becomes low, and it is not necessary to have a high demand as a known electron emission device. The excitation energy 'so that when the excitation energy is small' can also achieve high electron emission efficiency. Here, the maximum film thickness of the metal oxide layer is preferably smaller than the maximum diameter of the carbon nanotubes. Further, the plurality of carbon nanotubes are oriented perpendicular to the surface of the substrate, and The length of the metal oxide layer on the front end portion of the aforementioned carbon nanotube in the vertical direction on the surface of the substrate is preferably smaller than the maximum diameter of the aforementioned carbon nanotube. According to such a configuration, since only the metal oxide layer is selectively formed at the front end portion of the nanosoil back tube, it is possible to ensure that the sharpest moon 'J end portion of the surface of the carbon nanotube having the strongest electric field strength forms a barrier height on the surface. The lowest part. Further, since each of the carbon nanotubes is oriented in the direction of electron emission, electron emission having uniform characteristics can be surely obtained from the tip end portions of the respective carbon nanotubes. As a result, the electron emission efficiency can be further improved. Further, the metal oxide layer is preferably formed between the plurality of carbon nanotubes. According to such a configuration, electrons excited on the side wall of the carbon nanotube can also be removed in a vacuum by the effect of the metal oxide. As a result, even if the electrons are not emitted to the tip end portion of the carbon nanotubes, the time until the excitation is irradiated can be shortened, so that the electron emission efficiency can be further improved. Further, the metal oxide layer is preferably formed inside the carbon nanotube. According to such a configuration, electrons excited inside the carbon nanotubes away from the surface of the carbon nanotube can also be removed in a vacuum by the effect of the metal oxide. As a result, even if the electrons do not reach the tip end portion of the carbon nanotube, the time is elapsed, and the time until the radiation is excited is shortened, so that the electron emission efficiency can be further improved. Further, the metal oxide layer preferably contains any one of Mg〇, Ba〇, Ca〇, Be〇, and SrO. According to such a configuration, since the metal oxide can use the energy level of the electron conduction band, the electrons that are excited by the carbon nanotubes and reach the conduction band can be removed from the surface and removed from the vacuum. The height of the barrier. As a result, the two electron emission efficiencies can be further improved. Furthermore, the present invention can also be used as an electromagnetic wave generating device, characterized in that it has a 90-millimeter carbon nanotube layer formed on a substrate and composed of a plurality of carbon nanotubes; a metal oxide layer formed in The carbon nanotube layer is in contact with the carbon nanotube layer; the light source is irradiated with pulsed light on the carbon nanotube layer; the first 1: pole is connected to the carbon nanotube layer And the second electrode 'is spaced between the metal oxide layer and the metal oxide layer, and is disposed opposite to each other. According to such a configuration, the electrons excited by the SEM-like pulsed light are not directly excited by sufficient energy even if they directly exceed the high work function of the nanocarbon f itself, and the hybrids are treated with gold (W) The coffee is dislocated from the electron emission surface to the true two. In addition, by using the pulse light that is irradiated on the carbon nanotube layer, the ultra-short_laser light of the time width below the 丨 is used, and the electromagnetic wave of the test (tewHertz) can be generated. As a result, a high-order mega-level electromagnetic wave generating device can be realized. [Embodiment] [Embodiment 1] An electronic placement surface r according to an embodiment of the present invention is schematically illustrated with reference to the drawings. The structure of the electron emission device of the present embodiment is schematically shown in Fig. 1 (a). Forming a carbon nanotube layer 12, M376890 on the η_-type SlC substrate 11, on the η_-type S1 substrate 11, is oriented in a vertical direction to the surface of the Slc substrate u, that is, the front end is opposite to the surface of the counter substrate U. The height of the direction and the number of fine carbon nanotubes. The carbon nanotube layer 12 was placed in a vacuum of lx10_5 Toit, and the Sic substrate u was subjected to an annealing treatment at a temperature of K)000C for 60 minutes, and was formed by subjecting si lin and retaining carbon. Further, an oxidized town (knight 0) layer 13 is formed on the carbon nanotube layer 12, which is in contact with the carbon nanotube layer 12 at a thickness of 100 nm or less, for example, a thickness of i 〇 nm. The φ MgO layer I3 is formed by depositing Mg 〇 on the carbon nanotube layer u by electron beam evaporation. The electron emission surface is composed of a layer 13 and a carbon nanotube layer 12. Further, an electrode 15 is disposed above the MgO layer 13, which is spaced apart from the Mg layer 13 by a gap 14 spaced apart from the Mg layer 13, and is opposed to the tantalum layer 13. The electrode 15 is an electrode capable of applying a positive bias voltage to the SiC substrate 11 and has an anode electrode that concentrates the emitted electrons. Further, a resistive electrode 17 electrically connected to the carbon nanotube layer 12 is formed on the back surface of the Sic substrate n. The power supply voltage 16 is connected to the electrode 15 and the resistance electrode Π, and a voltage is applied between the electrode 15 and the resistance electrode 17 . Further, the resistive electrode 17 is formed on the back surface of the other substrate n, but may be formed on the surface of the Sic substrate u by removing a part of the MgO layer 13 and the carbon nanotube layer 12. Fig. 1 (b) and Fig. 1 (c) are a cross-sectional view and a top view, respectively, showing a detailed structure of the outermost surface of the electron emitting surface. The carbon nanotube layer 12 formed on the surface of the SiC substrate 11 is an average diameter composed of an average of five carbon faces as shown in Fig. i(b) (the carbon nanotube M376890 in the X direction of Fig. 1(b)) Each of the lengths of the 11 〇 nm multi-walled carbon nanotubes i2a is composed of a variety of carbon nanotubes, and each of the carbon faces is formed to have a specific surface distance and the outermost surface is closed. The front end portion (Fig. A) of the carbon nanotube 12a is formed into a shape of a pointed shape. Above the carbon nanotube thus constructed, a Mg layer 13 deposited by electron beam evaporation is formed. The tonnage layer 13 is composed of the following:

Mg013a' selectively migrates to the front end portion of the carbon nanotube, and the length in the vertical direction is smaller than the maximum diameter of the carbon nanotube 12a, and is located at the front end portion of φ square;

Mg013b is formed in a portion other than the front end portion. The formation of the rear end portion of the carbon nanotube 12a is such that the front end portion of the carbon nanotubes is an ideal carbon surface, and the graphite-type carbon atoms are arranged to collapse and form a rearrangement of atoms. 'And it shows extremely high reactivity to heterogeneous atoms and molecules. At this time, the maximum _thickness β (the maximum length of the nanometer tube in the χ direction of the maximum recording c (turn) of the length of the γ layer in the gamma direction γ direction is thinner) . It is desirable to control the formation of the carbon nanotube layer 13 by 10 or less of the maximum diameter of the carbon nanotubes. According to the front end portion, a film thickness and a layer of a portion on the front end portion of the carbon nanotube layer 12a of the carbon nanotube layer η are formed by selectively increasing the amount of coating. The film thickness of the portion other than the portion on the front end portion of the class 13 is thicker. ·, 16 and in the electron emission device having such a structure, by the source of electricity

The SiC substrate u is relatively biased with a positive bias voltage, whereby electrons in the carbon nanotube layer 12 are emitted from the surface, and the emitted electrons move to the gap 14. Figure 2 is an energy diagram of the electron emission surface. Further, Fig. 2 (&) is a graph in which the positive voltage is applied from the surface vacuum side 31 to the month b when the surface is not covered by the carbon nanotube layer 2 of the Mg layer 13. Fig. 2(b) is a graph showing the energy when a positive voltage is applied from the surface vacuum side 31 to the surface of the carbon nanotube layer 包覆2 covered by the MgO layer 13. According to Fig. 2(a), in the surface of the carbon nanotube layer U which is not covered by the layer π, the electrons in the carbon nanotube layer 12 are directly passed over the equivalent of the carbon nanotube itself. The obstacles 32 in the work function ψΜ are radiated by the channel through the barrier 33 and on the surface vacuum side 3 . On the other hand, the root meaning 2 = 'in the surface of the carbon nanotube layer 12 covered by the layer 13 is excited in the nano-anti-s layer 12? Lai Caisong's energy is close to the energy path E, which is transmitted by the EC, or is emitted by the surface vacuum (4), so it is in the surface of the carbon nanotube layer 12 covered by the Mg layer π. The electrical barrier = surface barrier is highly reduced to the degree of electron affinity X (usually below 2 eV), and the excitation energy necessary for the emission of electrons from the surface + _ , I from the surface: The figure of the electric-electrical device having the above-described structure will be described with reference to Fig. 3, which shows the money-electricity (four) scale of the electric power. In Fig. 3 t 'solid line (turn!) surface flow ~ voltage secret, (four) (10) The electric electron emission, the line Ιί} of the ΜΙ子子麟装置 indicates the current of the above-mentioned structure of the radiation device without using MgO-_ The curve, the dotted line (curve ίπ) is a current-voltage characteristic curve of the above-structured electron emission device in which M376890 does not use MgO' and each of the carbon nanotubes is not oriented in the carbon nanotube layer. Since the curve II and the line curve m of FIG. 3 are not the same, when the respective carbon nanotubes are twisted and the applied voltage when the electric field emission current exceeds 〇〇1 μΑ is defined as the threshold voltage, the threshold voltage is It is reduced by about 5 〇ν from about 35 〇ν (curve ΗΙ) to about 300 V (curve II), and the current value is also increased by about 10 times compared with the applied voltage of 325 V. This is to increase the strength of the pumping electric field at the front end of each carbon nanotube by orienting each carbon nanotube phase. On the other hand, since the curve 线 and the line curvature m are not the same, the threshold voltage is reduced by about 5 〇V by covering each of the carbon nanotubes with MgO, and the current value is further increased by about 丨G times. . This is due to the fact that it will accumulate on the carbon carbon, which makes the electrons get out of the surface with low barriers and increases the electron emission efficiency. The above carbon nanotubes are coated with MgO as described above. Therefore, even if the barrier height of the electronic batch meter (4) becomes low and the applied voltage of the voltage source is small, the electrons are radiated to the outside. That is, since it is not necessary to require a high excitation energy as in the conventional electron emission device, the electron emission efficiency of the south is achieved even when the excitation energy is small. Further, according to the electron emission device of the present embodiment, the carbon nanotube system is oriented in the electron emission direction and the front end portion of the oriented carbon nanotube is covered (four). Therefore, the electron emission efficiency can be improved because the electrons emitted from the carbon nanotubes are easily radiated from the front end portion into the vacuum. At this time, the gap between the carbon nanotubes is also reflected in the vaporization of the MgO. Therefore, 12 M376890 also emits electrons from the sidewalls of the carbon nanotubes deposited on the sidewalls of the carbon nanotubes. Further, according to the electron emission device of the present embodiment, since the emission direction of the electrons is "H", the electron emission from the tip end portion of the carbon nanotube can be surely performed. Therefore, it can improve the electron emission efficiency. Further, in the electron emission device of the present embodiment, as shown in Fig. 4, the MgO layer 13 has ...

The MgU J3C is a gap between the wind and the glutinous rice carbon tube 12a. MgO 13d ' is formed inside each of the carbon nanotubes (2). By such a configuration, it is possible to move away from the side soil and the inner wall of the front end portion of the carbon nanotube; | MgO emits electrons to a vacuum, and the electron emission efficiency can be improved. The difficulty of the creation of this creation is shown in Figure 5, that is, initially at the temperature: 17_C 'time: 2 〇 minutes, pressure · 1 〇 _ 2pa, oxygen partial pressure (10) conditions, the substrate is annealed The carbon nanotubes are grown (step su). Thereafter, the front end portion of the carbon nanotube is subjected to thermal oxidation at a temperature of 7 〇〇〇c 'time: 2 〇 minutes, pressure: atmospheric ' 'oxygen partial pressure of 20%, and the thermally oxidized portion is given The portion of the front end portion of the carbon nanotube is removed and opened (step S12). Then, at the end before the opening, using the electron beam evaporation method, under the condition of substrate temperature: fine c dust force: Chuan_milk, 'Mg〇 is evaporated to deposit Mg0 of the film thickness iOnm, thereby realizing Constituency. At the time of _ accumulation, finely selectively venting the voids and defects of the carbon nanotubes in the vacuum of Mg 将 will form 奈 Λ | | , , 。 。 。 。 。 。 。 。 。 。 。. This is because in the temperature range s, Mg0 is in the stack _, the energy age is more than the gap between the carbon tube and the defect — 13 M376890, while the carbon nanotube itself can maintain the mechanical shape. . Accordingly, the number of MgO formed inside the carbon nanotubes can be increased. Further, the opening of the front end portion of the carbon nanotube is also performed by irradiating the electron fiber to the front end portion of the carbon nanotube and removing the front end portion. [Embodiment 2] Fig. 6 is a cross-sectional view schematically showing the structure of an electromagnetic wave generating apparatus of the present state. • As shown in Fig. 6, the carbon nanotube layer 12 is formed on the n-type SiC substrate 11, and is composed of a plurality of carbon nanotubes having a height of 200 Å which is oriented in the vertical direction on the surface of the Sic substrate 11. The carbon nanotube layer 12 was placed in a vacuum of lxi〇_5T〇rr, and the Sic substrate 11 was annealed at a temperature of 10000 C for 60 minutes, and was formed by removing the meaning and leaving carbon. Further, the MgO layer 13 is formed on the carbon nanotube layer 12, and is in contact with the carbon nanotube layer 12 at a thickness of 10 nm or less, for example, a thickness of 1 〇 nm. The Mg · layer 13 is formed by depositing MgO on the carbon nanotube layer 12 by electron beam evaporation. The electron emission surface is composed of the MgO layer 13 and the carbon nanotube layer 12. Here, the electron emission surface composed of the MgO layer 13 and the carbon nanotube layer 12 illuminates the ultrashort pulse light train 28 of the transmission electrode 25 and the substrate 26. The ultrashort pulse train 28 is light having a smaller energy than the electron affinity X of the barrier height when the electrons are ejected from the electron emission surface, for example, a wavelength of 780 nm, a pulse width of 1 〇〇 fs, and a repetition frequency of 50 MHz. The pulsed light is generated at the laser source 27. Further, an electrode 25 is disposed above the MgO layer 13 so as to be spaced apart from the layer 13 of the Mg〇14 M376890 by a gap μ, and the layer 25 of the layer 13 can be opposite to the sic substrate 11 A film having a positive bias voltage of 20 (1 to 1 Torr) and having an anode electrode that bundles blue electrons is applied. The electrode 25 is formed on the substrate % composed of the ring gas. ,in

The lunar surface of the SiC substrate 11 is formed such that a resistor electrode electrically connected to the carbon nanotube layer η is electrically connected to the electrode 25 and the Wei electrode 17, and a voltage is applied between the electrode 25 and the resistance electrode 17. The resistive electrode 17_ is formed on the back surface of the substrate I!, but a portion of the Mg0 (four) and the carbon nanotube layer 12 may be removed to form a surface of the SiC substrate 11.乂 In addition, the electron emission surface is formed in the same manner as the electron emission surface shown in Figs. 1(b) and (6). That is, the carbon nanotube layer η formed on the surface of the Sic substrate u is composed of a plurality of nano-walls of the average layer 11 () of the flat layer & Each of the carbon nanotubes 12 & is formed such that each carbon surface has a structure in which a specific surface distance is maintained and the outermost surface is closed. The tip end portion of each of the carbon nanotubes has a sharp shape. An MgO layer 13 which is deposited by electron beam evaporation is formed on the carbon nanotube Ua. The % layer 13 is composed of the following:

MgOlh, which selectively migrates in the vertical direction of the front end portion of the carbon nanotube, is smaller than the maximum diameter of the carbon nanotube 12a and is located above the front end portion.

Mg013b' is formed in a portion other than the front end portion. 1 liter/migration migrates to the front end portion of the carbon nanotube 12a # Mg〇13a, which is a graphite-type carbon atomic array collapsed at the tip end portion of the carbon nanotube 12a, and is destroyed and formed. The defect structure of the atom is arranged, and the reactivity of the hetero atom and the molecule is extremely high. At this time, the maximum film thickness is thinner than the maximum diameter of the carbon nanotube 12a. It is preferable to control the temperature of the SiC substrate 11 to be equal to or less than 1 ’c of the maximum diameter of the carbon nanotube 12a to be formed to form an Mg ruthenium layer. According to this, it is possible to selectively form a more coating amount of the MgO layer 13 at the front end portion of the carbon nanotube 12a. In the electromagnetic wave generating apparatus having such a configuration, a positive bias voltage is relatively applied to the SiC substrate 11 by the voltage source 16, and the ultra-bright light series 28 generated by the laser light source is irradiated onto the electron emitting surface. Accordingly, electrons in the carbon nanotube layer 12 are emitted from the electron emitting surface. The electron group 29 which is irradiated by the electric layer 13 and is concentrated on the electrode 25 forms a pulse current which is irradiated with a laser pulse for a wide range of time, and flows between the electrode 电子 and the electron emitting surface. . Here, an electromagnetic wave 3 具有 having an electric field intensity proportional to the temporal change rate of the instantaneous current is generated. At this time, since the frequency of the generated electromagnetic wave is substantially the same as the above-mentioned instantaneous electric_pulse width_reverse scale, the region where the axis w is bribed is also the mega-level, the wavelength of the electromagnetic wave and the wavelength of the electromagnetic radiation surface. The level is integrated and made into ΙΟμηι. Next, the characteristics of the electromagnetic wave generating apparatus having the above configuration will be described with reference to -7. Fig. 7 is a diagram showing the power frequency of the electromagnetic wave generated by the electromagnetic wave generating device, and the solid line (recorded (10) indicates the turn of the upper touch, and the generated electric power is ambiguous (scale Q, lin (representing that Mg0 is not used) The power spectrum of the electromagnetic wave generated by the M376890 produced by the electromagnetic wave generating device of the above-described structure is special. According to Fig. 7, the electromagnetic wave generating device of the actual fine state is the electromagnetic wave generating device of the electromagnetic wave generating device without using Mg, The improvement is nearly 1 time. This is because the result of using MgO on the photoelectric surface, as shown in Fig. 3, the radiation current is improved by only 10 times. As described above, the electromagnetic wave generating apparatus according to the present embodiment, by For the same reason as in the first embodiment, even when the excitation energy is small, high electron emission efficiency can be achieved. Further, a mega-wave is generated by electron emission. Therefore, a high-output mega-wave generation device can be realized. Further, in the electron emission device of the present embodiment, the metal oxide deposited on the carbon nanotube layer is exemplified by MgO, but if it is a group 2 oxide, it is not limited thereto, and instead In the electromagnetic wave generating apparatus of the present embodiment, the substrate on which the metal oxide is formed is exemplified as a SiC substrate, but a substrate containing carbon is used. It is not limited to this, and the same effect can be obtained by using another substrate. [Illustration of the drawing] [Fig. 1] (a) schematically shows the electron emission device of the embodiment of the present creation (b) A cross-sectional view showing the detailed structure of the outermost surface of the electron-emitting surface. (c) The top view showing the detailed structure of the outermost surface of the electron-emitting surface. [Fig. 2] (8) Self-surface vacuum side Energy diagram of the electron emission surface when a positive voltage is applied to the surface of the carbon nanotube layer not covered by the Mg layer. 17 iVJJ/Ο卿(b) Applying positive electric dust from the surface vacuum side to the surface by the MgO layer Energy diagram of the electron emission surface when the carbon nanotube layer is coated. y Figure 3] shows a current-voltage characteristic curve of the electron emission device. Fig. 4] shows the detailed structure of the outermost surface of the electron emission surface. Sectional view. ^ Figure 5] Table (Fig. 6) schematically shows a cross-sectional view of the electromagnetic wave generating device of the second embodiment. [Fig. 7] shows the power spectrum characteristics of electromagnetic waves generated by the electromagnetic wave generating device. Fig. 8 is a view schematically showing a configuration of a conventional electronic radiation device. [Main component symbol description] 11 SiC substrate 12 carbon nanotube layer 12a carbon nanotube 13 magnesium oxide (MgO) layer

13a, 13b, 13c, 13d MgO

14 Void 15、25 Electrode 16 Voltage source 17 Resistive electrode 26 Substrate 27 Laser source 28 Ultrashort pulse light series 29 Electron group 30 Electromagnetic wave

Claims (1)

Sixth, the scope of application for patents: Bu-type electronic device, the frequency is characterized by: the Neridu tube layer's filaments are formed on the substrate, and the carbon nanotubes are oriented to the surface of the substrate and are perpendicular to the vertical number of the carbon nanotubes. a metal oxide layer formed on the carbon nanotube layer and in contact with the carbon nanotube layer; T first electrode connected to the carbon nanotube layer; and second The electrodes are spaced apart from the metal oxide layer and disposed opposite each other. 2. The electron emission device of claim 1, wherein the maximum thickness of the metal oxide layer is smaller than the maximum diameter of the carbon nanotube. 3. The electron emission device of claim 1, wherein the length of the metal oxide layer on the portion of the carbon nanotubes in the vertical direction of the substrate table is longer than the carbon nanotubes. The largest diameter is smaller. 4. The electron emission device according to claim 1, wherein the metal oxide layer is formed between the plurality of carbon nanotubes. 5. The electron emission device according to claim 1, wherein the metal oxide layer is formed inside the carbon nanotube. 6. The electron emission device according to the first aspect of the patent application, wherein the metal oxide layer contains any one of MgO, Ba〇, Ca〇, Be〇, and sK). U376890 7. The electronic filming pot of the first part of the metal oxide layer is thicker and the part of the front part of the metal oxide layer is thicker. And an electromagnetic wave generating device which is disposed on the front end portion of the carbon nanotube layer of the metal oxide layer, and is characterized in that: the carbon nanotube layer is formed on the substrate, and is composed of a plurality of The carbon nanotubes are composed of a layer of ruthenium, which is a pure red tube of the sacred silk, and a carbon source of the surface of the nano-carbon, which is irradiated with pulsed light on the aforementioned carbon nanotube layer; a first electrode which is connected to the aforementioned carbon nanotube layer; and a second electrode which is separated from the metal oxide layer and which is opposite to each other