Helical Microtubules of Graphitic Carbon", S. Iijima,Helical Microtubules of Graphitic Carbon", S. Iijima,
先前之奈米碳管場發射電子源一般至少包括一導電義 =作奈米碳管’該奈米碳管形成於該導電: 機械方法與原位生長法。 ^主要包括 μ浐摄玳人/、中機械方法係通過原子力顯 、’兄….° 之奈米碳管，將奈米碳管用導電膠固定到 1310201 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種場發射電子源及其製造方法，尤其涉 及一種奈米破管場發射電子源及其製造方法。 【先前技術】 奈米碳管（Carbon Nanotube，CNT)係一種新型碳材 料，由日本研究人員Iijima於1991年發現，請參見The previous nanocarbon field emission electron source generally includes at least one conductivity = nanocarbon tube. The carbon nanotube is formed on the conductivity: mechanical method and in situ growth method. ^Mainly includes μ浐photo玳/, the Chinese mechanical method is through the atomic force display, 'brothers..° nano carbon tube, the carbon nanotubes are fixed to 1310201 with conductive adhesive. 9. Invention: [Technical field of invention] The invention relates to a field emission electron source and a manufacturing method thereof, in particular to a nano tube field emission electron source and a manufacturing method thereof. [Prior Art] Carbon Nanotube (CNT) is a new type of carbon material discovered by Japanese researcher Iijima in 1991. See also
Nature，v〇l· 354, p56 (1991)。奈米碳管具有極優異之導 電性能、良好之化學穩定性與大長徑比，且其具有幾乎接 近理論極限之頂部表面積（頂部表面積愈小，其局部電場愈 集中）’故奈米碳管於場發射真空電子源領域具有潛在之應 用前景。目前之研絲明，奈米碳管係已知最好之場發射 材料之-’其頂部尺寸錢奈米至幾十奈米，具有極低場 發射電壓（小於100伏）’可傳輸極大之電流密度，並且電 流極敎’制壽命長，故非常適合作爲-種極佳點電子 源，應用於掃描電子顯微鏡（Scanning Electron Microscope)、透射電子顯微鏡伽臟㈤加Electr〇n M1Cr〇SCOpe)等設備之電子發射部件中。 6 1310201 導電基體上，此種方法程序簡單，但操作不容易且效率低。 另，通過該方法得到之奈米碳管場發射電子源中奈米碳管 係通過導電膠钻覆於導電基體上，使用時，奈米碳管與導 電基體之電接觸狀態不佳，不易充分發揮奈米碳管之場發 射性能。 原位生長法係先在導電基體上鍍上金屬催化劑，然後 通過化學氣相沈積或電弧放電等方法在導電基體上直接生 長出奈米碳管，此種方法雖然操作簡單，奈米碳管與導電 基體之電接觸良好。然，奈米碳管與導電基體之結合能力 較弱，在使用時奈米碳管易脫落或被電場力拔出，從而導 ^場發射電子源損壞。而且，由於該方法無法㈣奈米碳 管之生長方向，故仍存在效率低且可控性差之問題。另， 該方法之生産成本亦較高。 此外，奈米碳管應用於場發射電子源往往需要通過奈 米碳管發射較大電流。根據福勒—諾德漢（F〇wler_N〇rdheim， F-N)方程，場發射電流之大小決定於局域電場大小及作為 場發射陰極之場發射電子源發射端之逸出功（Work Function)之大小。在相同大小電場之作用下，選擇具有 更低逸出功之材料作爲場發射電子源發射端能夠獲得更大 場發射電流。先前之奈米碳管場發射電子源雖然具有極佳 之場發射幾何結構與較高的場增強因數（Enhancement Factor) ’惟，奈米碳管本身之逸出功爲4 55電子伏特 (eV) ’僅與金屬鎢之逸出功相當。 【發明内容】 1310201 有鑑於此，有必要提供一種奈米碳管與導電基體結合 緊密、電性連接良好，且具有較低之逸出功，因而具有較 大場發射電流之奈米碳管場發射電子源。以及一種生産效 率高、成本低、可控性強之製造該奈米碳管場發射電子源 的方法。 一種奈米碳管場發射電子源，其包括：一導電基體， 該導電基體具有一頂部；及一奈米碳管，該奈米碳管一端Nature, v〇l. 354, p56 (1991). The carbon nanotubes have excellent electrical conductivity, good chemical stability and large aspect ratio, and they have a top surface area close to the theoretical limit (the smaller the top surface area, the more concentrated the local electric field). There is potential application prospect in the field of field emission vacuum electron source. At present, the research of silk, the carbon nanotubes are known to be the best field emission materials - 'the top size of the carbon nanometer to tens of nanometers, with very low field emission voltage (less than 100 volts)' can be transmitted very much The current density and the long life of the current are very suitable as an excellent source of electrons for Scanning Electron Microscope, Transmission Electron Microscope (V) plus Electron〇n M1Cr〇SCOpe) In the electronic emission part of the device. 6 1310201 On a conductive substrate, this method is simple, but not easy to operate and inefficient. In addition, the carbon nanotubes in the electron emission source of the carbon nanotube field obtained by the method are coated on the conductive substrate by the conductive rubber drill. When used, the electrical contact state between the carbon nanotube and the conductive substrate is not good, and is not sufficient. Play the field emission performance of the carbon nanotubes. The in-situ growth method firstly coats a metal catalyst on a conductive substrate, and then directly grows a carbon nanotube on the conductive substrate by chemical vapor deposition or arc discharge. Although the method is simple, the carbon nanotube is The electrical contact of the conductive substrate is good. However, the binding ability of the carbon nanotubes to the conductive substrate is weak, and the carbon nanotubes are easily detached or pulled out by the electric field force during use, thereby causing damage to the electron source of the field emission. Moreover, since this method cannot (4) the growth direction of the carbon nanotubes, there is still a problem of low efficiency and poor controllability. In addition, the production cost of the method is also high. In addition, the application of carbon nanotubes to field emission electron sources often requires large currents to be emitted through the carbon nanotubes. According to the F〇wler_N〇rdheim (FN) equation, the magnitude of the field emission current is determined by the local electric field size and the work function of the field emission electron source emitting end of the field emission cathode. size. Under the action of the same size electric field, a material with a lower work function can be selected as the field emission electron source emitting end to obtain a larger field emission current. The previous nanocarbon field emission electron source has excellent field emission geometry and a high field enhancement factor. However, the work function of the carbon nanotube itself is 4 55 electron volts (eV). 'Only equivalent to the work of metal tungsten. SUMMARY OF THE INVENTION 1310201 In view of this, it is necessary to provide a carbon nanotube field emission in which a carbon nanotube is closely combined with a conductive substrate, has good electrical connection, and has a low work function, thereby having a large field emission current. Electronic source. And a method for producing the electron source of the carbon nanotube field emission with high production efficiency, low cost and strong controllability. A carbon nanotube field emission electron source, comprising: a conductive substrate having a top portion; and a carbon nanotube having one end of the carbon nanotube
與該導電基體頂部電性連接，另一端沿該導電基體頂部向 外延伸；其中，該奈米碳管場發射電子源進一步包括一表 面G飾層至形成於該奈来碳管向外延伸之一端之表面， 該表面修飾層之逸出功低於奈米碳管之逸出功。 該表面修飾層覆蓋整個奈米碳管與導電基體之表面。 該表面修飾層材料爲六硼化鑭或金屬鑭。 該六硼化鑭之逸出功爲2.62電子伏特。 吻衣囬珍哪層之厚度爲1〜10奈米。 該導電基體之頂部爲轉、圓臺形或挺形。 該導電基體材料可選㈣、金、錮或^ 該奈米碳管爲多壁奈米碳管。 該奈米碳管之長度爲1(Μ⑽微米，直徑爲U 該奈米碳管之長度爲5〇微米，直徑爲15奈米。 —種奈米碳管場發射電子源之製造方法，包括1 使其相對之兩 (一）提供兩個頂部相對之導電基體 頂部共同浸人同-含奈米碳管之溶液令； 8 1310201 一）施加一父流電壓於該兩導電基體之間，以使至 少—奈米碳管組裝至該相對之兩頂部之間； (一）切斷兩導電基體之間之電流並移除上述兩導電 基體相對兩頂部之間之溶液； (四） 分開上述兩相對之導電基體，以使至少一奈米 碳管附著於至少一導電基體之頂部； ’ (五） 形成-表面修飾層至少覆蓋該奈米碳管用於發 射電子一端之表面。 步驟（五）中表面修飾層之形成方法包括磁控賤射法 或電子束蒸發法。 步驟㈠中所述之含奈米碳管之溶液包括作爲主要 溶劑之異丙醇與用作穩定劑之乙基纖維素。 步驟㈠中所述之相對之兩頂部之間之距離爲10〜20 微米。 步驟（二）中進一步包括以下步驟：監控奈米碳管之 組裝過程，以確定奈米碳管組裝於該兩相對之導電基體 部之間。 所述之監控方法包括：在兩導電基體所在之電路中串 聯一個電阻；在該電阻兩端並聯一示波器。 相較于先刖技術’奈米碳管場發射電子源中奈米碳管 與導電基體結合緊密、連接良好，奈米碳管表面之表 面修飾層可財效降低奈米碳管場發魏子源電子發射端 之逸出功’同時維持奈米碳管原有之場發射幾何結構，在 相同大小的發射電場作用下，該奈錢管場發射電子源具 .1310201 有更高之電子魏密度與發射電流。奈米碳管場發射電子 源之製造方法只需钱秒至幾十秒，耗時短，效率高。且， 整個組裝過程均可實現自動化操作與監測，提高生産效 率，可控性強。同時所需之生産設備簡單，生産成本低， 適。進行大她生産。另’奈米碳管之表面修飾過程能夠 在維持奈#碳管極佳場魏幾何賴之基礎上，降低奈米 石反官場發射電子源奈米碳管電子發射端之逸出功，進而能 夠增大該奈米碳管場發射電子源之場發射電流，有利於增 強奈米碳管場發射電子源之場發射性能。 【實施方式】 下面將結合附圖對本發明作進一步之詳細說明。 請參閱圖1與圖2，本發明實施例提供一種奈米碳管 場發射電子源10，該奈米碳管場發射電子源1〇包括一導 電基體12、一奈米碳管14與一表面修飾層16。該導電基 體12由導電材料製成，如鎢、金、鉬、鉑等。爲測量方便， 本實施例導電基體12採用表面鍍有金層之原子力顯微鏡 18 (Atomic Force Microscope, AFM)之探針。該導電基 體12具有一頂部122 ’該頂部122爲錐形。該奈米碳管14 之第一端142與該導電基體12之頂部122電性連接，並通 過凡德瓦爾力附著於該導電基體12上。該奈米碳管14之 第二端144沿該導電基體12之頂部122向遠離導電基體 12之方向延伸’作爲該場發射電子源1〇之電子發射端。 本實施例中’該奈米碳管14爲一多壁奈米碳管，其直徑範 圍爲1〜50奈米’優選爲15奈米，長度範圍爲1〇〜1〇〇微米， 1310201 優選爲50微米。絲面修飾層16至少覆蓋該奈米碳管i4 2電子發射端之第二端144之表面，用於增大該碳納米 &場發射電子源10㈣發射電流。該表面修飾層16材料 j出功低於奈米碳管14之逸出功，城均勻分佈于奈米 碳管14之表面，並與奈米碳管14 f密結合。優選地，該 表面修飾層16材料選用六靴鑭或金屬鑭，其中，六蝴化 鑭之逸出功爲2.62電子伏特，低於奈米碳管之逸出功 (4. 55電子伏特）。該表面修飾層16之厚度爲卜1〇奈米， 優選爲5奈米。本實施例中，該表面修飾層16也可覆蓋整 個不米碳S U與導電基體12之表面。由於奈米碳管14作 爲電子發射端之第二端144表面覆蓋有比奈米碳管14更低 逸出功之表面修飾層16 ’在相同大小之電場作用下，該奈 米碳管場發射源10之發射電流比先前之奈鱗管場發: 電子源之發射電;^顯著增大。本實施例+採用六蝴化爛或 金屬鑭作絲面修飾層16之奈米碳管場發射電子源10之 場發射電流可達到140微安培，優選爲45，微安培，電 流發射密度可達到7. 9xlG7A/an2。進-步地，經測量，本 實施例奈米碳管場發射電子源1G場發射電流爲45〜65微安 培時’可連續發射電子5萬秒未發現衰竭現象，因而，該 經過表面修飾之奈米碳管場發射電子源10具有良好之壽 命。 另，本發明實施例中導電基體12還可依實際需要設計 成其他形狀。該導電基體12之頂部也可爲其他形狀，如圓 臺形或細小之柱形，而不限於錐形。本實施例之奈米碳管 11 1310201 場發射電子源ίο可應用於場發射平板顯示器、電子搶、微 波放大器、X射線源或電子束平板印刷等場發射電子源裝 ' 置。 * 請參閱圖3與圖4，本發明實施例提供一種製造奈米 破管場發射電子源之方法，主要由以下步驟組成。 (一） 提供兩導電基體32與42 ,其分別具有錐形頂 部322與422。使該兩頂部322與422相對設置，並間隔 開一疋距離。移取少量含奈米碳管之溶液於該兩頂部 _ 322與422之間，並使兩者能共同浸入該溶液中。 (二） 對該兩導電基體32與42施加一交流電壓6〇， 直到至少一奈米碳管組裝於該兩頂部322與422之間。 (三） 切斷兩導電基體32與42之間之電流並移除上 述兩導電基體相對兩頂部322與422之間之溶液5〇。 (四）分開上述兩相對之導電基體32與42，以使至 著於至少-導電基體之頂部，峨碳Electrically connected to the top of the conductive substrate, the other end extending outwardly along the top of the conductive substrate; wherein the carbon nanotube field emission electron source further comprises a surface G decorative layer formed to extend outwardly from the carbon nanotube On the surface of one end, the work function of the surface modification layer is lower than the work function of the carbon nanotubes. The surface modification layer covers the entire surface of the carbon nanotube and the conductive substrate. The surface modification layer material is lanthanum hexaboride or metal ruthenium. The work function of the lanthanum hexaboride is 2.62 eV. The thickness of the kiss back to the layer is 1~10 nm. The top of the conductive substrate is a turn, a truncated cone or a stiff shape. The conductive base material may be selected from (4), gold, rhodium or ^. The carbon nanotube is a multi-walled carbon nanotube. The carbon nanotube has a length of 1 (Μ(10) micrometer and a diameter of U. The carbon nanotube has a length of 5 μm and a diameter of 15 nm. - A method for manufacturing a nanocarbon field emission electron source, including 1 Having two opposite ones (one) providing a solution of the top of the conductive substrate on the top opposite to the same - containing carbon nanotubes; 8 1310201 a) applying a parent current voltage between the two conductive substrates so that At least - a carbon nanotube is assembled between the opposite tops; (a) cutting off the current between the two conductive substrates and removing the solution between the two conductive substrates opposite the top; (iv) separating the two opposite a conductive substrate such that at least one carbon nanotube is attached to the top of at least one of the conductive substrates; '(5) forming a surface modifying layer covering at least the surface of the carbon nanotube for emitting electrons. The method of forming the surface modification layer in the step (5) includes a magnetron sputtering method or an electron beam evaporation method. The carbon nanotube-containing solution described in the step (1) includes isopropanol as a main solvent and ethyl cellulose as a stabilizer. The distance between the opposite tops described in step (1) is 10 to 20 microns. The step (2) further includes the step of monitoring the assembly process of the carbon nanotubes to determine that the carbon nanotubes are assembled between the two opposite conductive bases. The monitoring method includes: connecting a resistor in a circuit in which the two conductive substrates are located; and an oscilloscope connected in parallel across the resistor. Compared with the prior art, the carbon nanotubes in the electron emission source of the carbon nanotubes are closely combined with the conductive matrix, and the surface modification layer on the surface of the carbon nanotubes can reduce the carbon nanotube field and send Weiziyuan electrons. The work function of the emitter is 'while maintaining the original field emission geometry of the carbon nanotubes. Under the action of the same size of the field, the electron source of the net field is emitted. 1310201 has a higher electron density and emission. Current. The manufacturing method of the carbon nanotube field emission electron source takes only a few seconds to several tens of seconds, which is short in time and high in efficiency. Moreover, the entire assembly process can achieve automatic operation and monitoring, improve production efficiency and controllability. At the same time, the production equipment required is simple, and the production cost is low and suitable. Carry out her big production. In addition, the surface modification process of the carbon nanotubes can reduce the work function of the electron emission end of the nano-carbon nanotubes in the counter-official field emission electron source based on the excellent geometry of the carbon nanotubes. Increasing the field emission current of the electron source of the carbon nanotube field is beneficial to enhancing the field emission performance of the electron source of the carbon nanotube field. [Embodiment] Hereinafter, the present invention will be further described in detail with reference to the accompanying drawings. Referring to FIG. 1 and FIG. 2, an embodiment of the present invention provides a carbon nanotube field emission electron source 10, wherein the carbon nanotube field emission electron source 1 includes a conductive substrate 12, a carbon nanotube 14 and a surface. The layer 16 is modified. The conductive substrate 12 is made of a conductive material such as tungsten, gold, molybdenum, platinum or the like. For the convenience of measurement, the conductive substrate 12 of this embodiment is a probe of an atomic force microscope 18 (AFM) surface plated with a gold layer. The conductive substrate 12 has a top portion 122' which is tapered. The first end 142 of the carbon nanotube 14 is electrically connected to the top portion 122 of the conductive substrate 12 and is attached to the conductive substrate 12 by a van der Waals force. The second end 144 of the carbon nanotube 14 extends along the top 122 of the conductive substrate 12 away from the conductive substrate 12 as the electron-emitting end of the field emission electron source. In the present embodiment, the carbon nanotube 14 is a multi-walled carbon nanotube having a diameter ranging from 1 to 50 nm, preferably 15 nm, and a length ranging from 1 to 1 μm, and 1310201 is preferably 50 microns. The surface finish layer 16 covers at least the surface of the second end 144 of the electron-emitting end of the carbon nanotube i4 2 for increasing the emission current of the carbon nano-amplifier electron source 10 (4). The material of the surface modification layer 16 is lower than the work function of the carbon nanotubes 14 and is uniformly distributed on the surface of the carbon nanotube 14 and closely bonded to the carbon nanotubes 14 f. Preferably, the surface modification layer 16 is made of six boots or metal crucibles, wherein the work function of the six-foaming crucible is 2.62 eV, which is lower than the work function of the carbon nanotubes (4.55 eV). The surface modification layer 16 has a thickness of 1 nm, preferably 5 nm. In this embodiment, the surface modification layer 16 may also cover the entire surface of the non-meter carbon S U and the conductive substrate 12. Since the carbon nanotube 14 is used as the surface of the second end 144 of the electron-emitting end, the surface modification layer 16' having a lower work function than the carbon nanotube 14 is subjected to an electric field of the same magnitude, and the carbon nanotube field emission source is used. The emission current of 10 is higher than that of the previous Nylon tube field: the emission of the electron source; ^ significantly increased. In this embodiment, the field emission current of the carbon nanotube field emission electron source 10 using the six-foaming or metal ruthenium-finishing layer 16 can reach 140 microamperes, preferably 45, microamperes, and the current emission density can be reached. 7. 9xlG7A/an2. Further, after measuring, the field emission current of the carbon nanotube field emission electron source of the present embodiment is 45 to 65 microamperes, 'the continuous emission of electrons for 50,000 seconds is not found to be exhausted, and thus the surface modification is performed. The carbon nanotube field emission electron source 10 has a good lifetime. In addition, in the embodiment of the present invention, the conductive substrate 12 can be designed into other shapes according to actual needs. The top of the conductive substrate 12 may also have other shapes, such as a truncated cone shape or a thin cylindrical shape, without being limited to a taper. The carbon nanotube 11 1310201 field emission electron source of the present embodiment can be applied to a field emission electron source device such as a field emission flat panel display, an electronic grab, a microwave amplifier, an X-ray source or an electron beam lithography. * Referring to FIG. 3 and FIG. 4, an embodiment of the present invention provides a method for fabricating a source of electron emission from a nanotube field, which is mainly composed of the following steps. (i) Two conductive substrates 32 and 42 are provided which have tapered top portions 322 and 422, respectively. The two tops 322 and 422 are disposed opposite each other and spaced apart by a distance. A small amount of a solution containing carbon nanotubes was pipetted between the two tops 322 and 422, and the two were co-immersed in the solution. (2) Applying an alternating voltage of 6 对该 to the two conductive substrates 32 and 42 until at least one carbon nanotube is assembled between the two top portions 322 and 422. (iii) cutting off the current between the two conductive substrates 32 and 42 and removing the solution 5 上 between the two conductive substrates opposite the tops 322 and 422. (d) separating the two opposite conductive substrates 32 and 42 so as to be at least the top of the conductive substrate, tantalum carbon
，以使至 而不限於錐形。另，當頂部322與422 在組裝奈米碳管之過程中最好使兩項部 12 1310201 322與422之部分端面相對設置，如兩端面之邊緣相對設 置。另*，該兩頂部322與422之間之距離應根據所採用= 奈米碳管長度加以設定，最好與奈米碳管長度相近，不宜 太大，否則不利於組裝。該間隔距離一般小於10〇微来， 優選爲10〜20微米。 ； 所述之含奈米碳管的溶液50係以異丙醇爲主要溶 劑，通過超聲震蕩之方法使奈米碳管在其中均勻分散而得 到的。爲使該溶液50穩定，還可加入少量的乙基纖維素: 奈米碳管爲採用低壓化學氣相沈積（L〇w POSSUM Chemical Vapor Deposition，LP_CVD)合成之多壁奈米碳 管。當然’溶液5Q還可採用其他方法製備，例如採二其: 溶劑、穩定劑或者增加分離過_處理步驟，以得到均勾 穩定的奈米碳管溶液爲宜，不似具體實施例爲限。 另，溶液50之濃度可能影響後期被組裝之奈米碳管數 量。:般，溶液50濃度越大’後期則較容易組裝上多根奈 米厌苔因此，可根據實際需要調配溶液50之濃度，如只 裝-根奈米碳管，則應儘量降低溶液5()之濃度。反之， 也可以通過婦絲5Q之濃度，在—定程度上控制被組裝 之奈米碳管數量。爲避免發射電子時，奈米碳管之間之相 互干擾影響’本實施m根奈米碳衫導電基體上。 溶液50可由吸管、移液管、注射器或其他適宜之裝置 移取並施加於導電基體頂部322與422之間。所施加之溶 液50不宜過多，以使該兩頂部322與422能共同浸入同一 滴溶液50即可。另，也可將兩頂部322與概直接浸入少 13 Ϊ310201 量由燒杯等容器盛放之溶液50中。該溶液5〇需移除時， 只需同樣通過吸管、移液管、注射器或其他適宜之裝置移 取即可，當兩頂部322與422係、直接浸入少量由燒杯等容 盗盛放之溶液50㈣，只需將兩頂部322與422從溶液 50中移出即可。 另外，步驟（二）卜所述之交流電壓之峰值最好在 U)伏以内，醉在丨千至1G域狀間。本實施例主要 t據雙向電泳法顧：在交流1場巾’溶液5G中之奈米 h向電％強度大之方向運動，最終運酬顧最大之兩 頂部322與422相對之區域’並被吸附到該兩頂部322與 422上。此後，奈米碳管依靠與該兩頂部犯2與之凡 德瓦爾力牢固吸附在頂部322與422之表面上。一般，通 ，時間只需幾秒至幾切、’因此馳裝方法耗時短 ，效率 向0 、步驟（五）中，該奈米碳管表面之修飾方法進一步包 括通過磁㈣射或電子束蒸發之方法形成―厚度爲卜1〇 奈米之表面修飾層於該奈㈣管表面。絲面修飾層應選 擇能與奈米碳管浸潤良好，轉㈣分針奈米碳管表面 之材料1重要的係’該表面修倚層材料之逸出功應低於 s之逸出功。優選的’本實施例通過磁控滅射之方 成—厚度爲5奈米之六慨爾或金屬爾於該奈米 反管與附著有奈米碳官之導電基體表面，該六蝴化爛之逸 出功爲2. 62電子伏特。另’由於奈米碳管主要通過其一端 七射電子’實際上只需控制形辆表面修飾層覆蓋該奈米 14 1310201 碳管發射電子之一端之表面即可。 • $可採用監測系統對整個奈米碳管組襄過程進行監 控’從而實現即時監控、即時調整，提高成品率。例如， 根據未組裝上奈米碳管之兩頂部322與似係處於斷路狀 態、而組裝上奈米碳管後該兩者係處於通路狀態，可方便 地對14兩個狀態進行監測。在本實施例中，採用之監測方 法係依據上述原理，在圖4所示之電路巾㈣—電阻（圖 中未顯不）’用不波器觀察該電阻兩端之波形變化。當波形 發生突變則表示奈米碳管已經組裝到兩個頂部322與似 之間，這時就可以降壓斷電並移走液滴。當然，也;]:以採 用其他監測方法及設備進行，不必限於本實施例。 進而，整個組裝過程均可實現自動化操作與監測，避 ^手動或半手動操作之偏差以及化學氣相沈積法中奈米碳 官生長之不可控性，提高生産效率，增強可控性，同時所 需之生產設備簡單，生産成本低，適合進行大規模生產。 丨 3，本發明實補可it-步製扯括乡個奈米碳管場 發射電子源之奈米碳管場發射陣列用於如平板場發射顯示 器中作爲電子發射源。可將形成有多個導電基體之一陰極 電極層直接浸入含有奈来碳管之溶液中。通過施加電壓於 該陰極電極層與另-可活動之導電基體，並將該可活動之 導電基體頂部逐一靠近形成於陰極電極層之導電基體頂 部’以將奈米碳管分別組裝於該多個導電基體上，最後通 過修飾奈米碳管表面形成表面修飾層即可。 請參閱圖5，從掃描電子顯微鏡照片可看出，奈米碳 15 1310201 官被組裝到原子力顯微鏡之尖端，並且已被拉直。其係因 • 爲奈米碳管組裝於兩頂部過程中在電場中被極化產生電偶 . 極距，兩端帶有電荷，電場對其作用力有一沿其軸向之分 力，使奈米碳管拉伸變直。 請參閱圖6，經測量，本實施例通過六硼化鑭修飾後 之奈米碳管場發射電子源之開啓電場強度約爲〇.7 v/#m (伏特/微米），低於修飾前之奈米碳管場發射電子源（約 1· 5 V/Am) ’修飾後之奈米碳管場發射電子源場發射電流 也顯著增大。另，經過測量，通過六硼化鑭修飾後之奈米 碳管場發射電子源對應于開啓電場強度之奈米碳管拔出力 爲14· InN (奈牛頓），低於修飾前之奈米碳管場發射電子 源（54. 4nN)。因此，修飾後之奈米碳管場發射電子源中奈 米碳管與導電基體結合緊密，且電性連接良好。 本發明奈米碳管場發射電子源之組裝方法一般只需要 幾秒至幾十秒，耗時短，效率高。並且，整個組裝過程均 可實現自動化操作與監測，提高生産效率，增強可控性。 同時所需之生産設備簡單，生産成本低，適合進行大規模 生産。另，奈米碳管表面之表面修飾層可以有效降低奈米 碳管場發射電子源電子發射端之逸出功，同時維持奈米碳 官原有之場發射幾何結構，在維持發射電場不變之情況 下，該奈米碳管場發射電子源具有更高之電子發射密度與 發射電流。 本技術領域技術人員應明白，本發明奈米碳管場發射 電子源的製造方法中也可通過現有的其他方式如顯微鏡操 16 1310201 縱組裝法或雜生長法絲奈米碳管於導電基體上，再通 過修飾奈米碳管的電子發射端部形成具有低逸出功的表面 修飾層’也可職增大奈米碳管場魏軒㈣發射電流。 綜上所述，本發明確已符合發明專利之要件，遂依法 提出專利申請。惟，以上所述者僅為本發明之較佳實施例， 自不能以此關本案之巾請專利範圍。舉凡熟悉本案技藝 之人士援依本發明之精神所作之等效修飾或變化，皆應涵 蓋於以下申請專利範圍内。 【圖式簡單說明】 一圖1爲本發明實施例之奈米碳管場發射電子源之立體 示意圖； 圖2爲圖1中π部分縱向剖視圖； 圖3爲本發明實施例奈米碳管場發射電子源之製造方 法之步驟示意圖； 圖4爲本發明實施例組裝奈米碳管場發射電子源之裂 置示意圖； 圖5爲本發明實施例奈米碳管場發射電子源之掃描電 子顯微鏡照片。 圖6為本發明實施例之奈米碳管場發射電子源修飾前 後之電流-電壓曲線對比示意圖。 【主要元件符號說明】 12 ， 32 ， 42 122 ， 322 ， 422 奈米碳管場發射電子源 導電基體 頂部 17So that it is not limited to a cone. In addition, when the top portions 322 and 422 are assembled in the process of assembling the carbon nanotubes, it is preferable to arrange the end portions of the two portions 12 1310201 322 and 422 oppositely, for example, the edges of the end faces are oppositely disposed. In addition, the distance between the two tops 322 and 422 should be set according to the length of the carbon nanotube used, preferably close to the length of the carbon nanotube, and should not be too large, otherwise it is not suitable for assembly. The spacing distance is generally less than 10 micrometers, preferably 10 to 20 micrometers. The carbon nanotube-containing solution 50 is obtained by uniformly dispersing a carbon nanotube in the form of isopropanol as a main solvent by ultrasonic vibration. In order to stabilize the solution 50, a small amount of ethyl cellulose may be added: The carbon nanotubes are multi-walled carbon nanotubes synthesized by low pressure chemical vapor deposition (L〇w POSSUM Chemical Vapor Deposition, LP_CVD). Of course, the solution 5Q can also be prepared by other methods, for example, by using a solvent, a stabilizer or an additional separation step to obtain a homogenous stabilized carbon nanotube solution, which is not limited to the specific examples. In addition, the concentration of solution 50 may affect the number of carbon nanotubes that are assembled later. : Generally, the higher the concentration of the solution 50 is, the later it is easier to assemble multiple nano-analyzed moss. Therefore, the concentration of the solution 50 can be adjusted according to actual needs. If only the carbon nanotubes are installed, the solution 5 should be reduced as much as possible ( The concentration of ). Conversely, the number of assembled carbon nanotubes can also be controlled to a certain extent by the concentration of the 5X. In order to avoid the emission of electrons, the mutual interference between the carbon nanotubes affects the conductive substrate of the m-nano carbon cap. Solution 50 can be removed by a pipette, pipette, syringe or other suitable device and applied between conductive substrate tops 322 and 422. The solution 50 to be applied is not excessive so that the two top portions 322 and 422 can be immersed in the same drop solution 50 together. Alternatively, the two top portions 322 may be directly immersed in a solution 50 containing a container of a beaker or the like in a volume of less than 13 Ϊ 310201. When the solution 5 needs to be removed, it only needs to be removed by a pipette, a pipette, a syringe or other suitable device. When the two tops are 322 and 422, the solution is directly immersed in a small amount of the solution. 50 (d), simply remove the two tops 322 and 422 from the solution 50. In addition, the peak value of the alternating voltage described in step (2) is preferably within U volts, and is drunk in the range of thousands to 1G. This embodiment mainly relies on the two-dimensional electrophoresis method: in the exchange of 1 field towel 'solution 5G, the nano h moves toward the direction of the electric % strength, and finally pays the highest area of the two top portions 322 and 422' and is Adsorbed onto the two tops 322 and 422. Thereafter, the carbon nanotubes were firmly attached to the surfaces of the tops 322 and 422 by virtue of the two top sins 2 and van der Waals forces. Generally, the pass time is only a few seconds to a few cuts, so the time for the galloping method is short, the efficiency is 0, and the step (5), the modification method of the surface of the carbon nanotube further includes magnetic (tetra) or electron beam evaporation. The method forms a surface modification layer having a thickness of 1 nanometer on the surface of the tube. The silk-finished layer should be selected to be infiltrated well with the carbon nanotubes. The material of the surface of the (four) minute-needle carbon nanotubes is important. The work function of the surface-repairing layer material should be lower than the work function of s. Preferably, the present embodiment is formed by a magnetically controlled shot-cutting layer having a thickness of 5 nm or a metal surface on the surface of the nano tube and the surface of the conductive substrate to which the carbon carbon is attached. The work function is 2.62 eV. In addition, since the carbon nanotubes mainly pass through one end of the electrons, it is only necessary to control the surface modification layer of the surface to cover the surface of one end of the electron emission electrons of the nano 14 1310201 carbon tube. • $ monitor system can be used to monitor the entire carbon nanotube stacking process to achieve immediate monitoring, immediate adjustment, and improved yield. For example, depending on whether the two tops 322 of the unassembled carbon nanotubes are in an open state and the carbon nanotubes are assembled and the two are in a passage state, 14 states can be conveniently monitored. In the present embodiment, the monitoring method employed is based on the above principle, and the waveform change at both ends of the resistor is observed by the non-magnetic device in the circuit board (4)-resistance (not shown) shown in Fig. 4. When the waveform is abrupt, it means that the carbon nanotubes have been assembled between the two tops 322 and the like, and then the voltage can be depressurized and the droplets removed. Of course, also;]: It is carried out by using other monitoring methods and equipment, and is not necessarily limited to this embodiment. Furthermore, the entire assembly process can achieve automatic operation and monitoring, avoiding the deviation of manual or semi-manual operation and the uncontrollability of nano-carbon growth in chemical vapor deposition, improving production efficiency and enhancing controllability. The production equipment required is simple, the production cost is low, and it is suitable for mass production.丨 3, the present invention can be used to process the nano carbon nanotube field. The carbon nanotube field emission array of the electron emission source is used as an electron emission source in a flat field emission display. The cathode electrode layer formed with one of a plurality of conductive substrates may be directly immersed in a solution containing a carbon nanotube. Applying a voltage to the cathode electrode layer and the other movable conductive substrate, and bringing the top of the movable conductive substrate one by one close to the top of the conductive substrate formed on the cathode electrode layer to assemble the carbon nanotubes to the plurality of On the conductive substrate, finally, a surface modification layer is formed by modifying the surface of the carbon nanotube. Referring to Figure 5, it can be seen from the scanning electron micrograph that the nanocarbon 15 1310201 is assembled to the tip of the atomic force microscope and has been straightened. The reason is that the carbon nanotubes are polarized in the electric field during the assembly of the carbon nanotubes to produce a galvanic couple. The pole distance has a charge at both ends, and the electric field has a force along its axial force, so that The carbon tube is stretched and straightened. Referring to FIG. 6, after measuring, the on-field electric field intensity of the nano-carbon nanotube field emission electron source modified by lanthanum hexaboride is about 7.7 v/#m (volt/micron), which is lower than before modification. The electron source of the carbon nanotube field emission (about 1.5 V/Am) 'The modified electron field emission current of the carbon nanotube field is also significantly increased. In addition, after measurement, the nano-carbon nanotube field emission electron source modified by lanthanum hexaboride corresponds to the opening electric field strength of the carbon nanotube pull-out force of 14·InN (Nylon), which is lower than the nanometer before modification. The carbon tube field emits an electron source (54. 4nN). Therefore, the carbon nanotubes in the modified carbon nanotube field emission electron source are tightly combined with the conductive substrate and have good electrical connection. The assembly method of the carbon nanotube field emission electron source of the present invention generally takes only a few seconds to several tens of seconds, which is short in time and high in efficiency. Moreover, the entire assembly process can achieve automatic operation and monitoring, improve production efficiency and enhance controllability. At the same time, the required production equipment is simple, the production cost is low, and it is suitable for mass production. In addition, the surface modification layer on the surface of the carbon nanotube can effectively reduce the work function of the electron emission end of the electron field of the carbon nanotube field emission, while maintaining the original field emission geometry of the carbon carbon official, while maintaining the emission field. In this case, the carbon nanotube field emission electron source has a higher electron emission density and emission current. It should be understood by those skilled in the art that the method for fabricating the carbon nanotube field emission electron source of the present invention can also be applied to the conductive substrate by other existing methods such as microscopy 16 1310201 longitudinal assembly method or heterogeneous growth method. Then, by modifying the electron-emitting end of the carbon nanotube to form a surface modification layer having a low work function, it is also possible to increase the emission current of the carbon nanotube field Wei Xuan (4). In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to claim the scope of the patent. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the present invention are intended to be included in the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a carbon nanotube field emission electron source according to an embodiment of the present invention; FIG. 2 is a longitudinal sectional view of a portion π in FIG. 1; FIG. 3 is a view of a carbon nanotube field according to an embodiment of the present invention; FIG. 4 is a schematic diagram showing the cracking of a field emission electron source for assembling a carbon nanotube according to an embodiment of the present invention; FIG. 5 is a scanning electron microscope of a field emission electron source of a carbon nanotube according to an embodiment of the present invention; photo. Fig. 6 is a schematic diagram showing a comparison of current-voltage curves before and after modification of a carbon nanotube field emission electron source according to an embodiment of the present invention. [Main component symbol description] 12 , 32 , 42 122 , 322 , 422 nm carbon nanotube field emission electron source Conductive substrate Top 17
1310201 奈米碳管 14 第一端 142 第二端 144 表面修飾層 16 原子力顯微鏡 18 溶液 50 交流電壓 601310201 Carbon nanotube 14 First end 142 Second end 144 Surface modification layer 16 Atomic force microscope 18 Solution 50 AC voltage 60
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