200827471 九、發明說明： 【發明所屬之技術領域】 ，本發明涉及-種奈米碳管陣列的製備方法，尤其涉及 採用雷射辅助化學氣相沉積法製備奈米碳管陣列的方法。 【先前技術】 不米故管係九十年代初才發現的一種新型一維奈米材 料。奈米碳管的特殊結構決定了其具有特殊的性質，如高 ⑩絲與高熱穩定性；隨著奈米碳管職方式的變化， 奈米碳管可呈現出金屬性或半導體性等。由於奈米碳管具 有理想的一維結構以及在力學、電學、熱學等領域優良的 性質，其在材料科學、化學、物理學等交叉學科領域已展 現出廣闊的應用前景，在科學研究以及產業應用上也受到 越來越多的關注。 目鈾比較成热的製備奈米碳管的方法主要包括電弧放 電法（Arc discharge)、雷射燒蝕法（Laser Ablation)及化 ⑩ 學氣相沉積法（Chemical Vapor Deposition)。其中，化學 氣相沉積法與前兩種方法相比具有產量高、可控性強、與 現行的積體電路工藝相相容等優點，便於工業上進行大規 权合成’因此近幾年備受關注。 用於製備奈米碳管的化學氣相沉積法一般包括傳統熱 化學氣相沉積法（Therma 1 Chemi ca 1 Vapor Depos i t i on， CVD)、等離子化學氣相沉積法（piasma Chemical Vapor Deposition，PCVD)與雷射輔助化學氣相沉積法 (Laser-Induced Chemical Vapor Deposition， LICVD)。 6 200827471 先鈿的雷射輔助化學氣相沉積法一般以雷射為快速加 熱熱源，利用雷射光束直接照射在生長所需的基底上使其 溫度升高，達到生長所需的溫度。當含碳反應氣體流經高 溫基底表面時，受基底影響升溫，通過與基底上的催化劑 作用，反應氣體產生熱解或化學反應，從而實現奈米碳管 的生長。 惟’先别的雷射輔助化學氣相沉積法生長奈米碳管有 以下不足之處：首先，該方法一般需要在一密封的反應爐 馨内進行，並使得反應氣體充滿整個反應空間，其設備較為 複雜，且難以製作大型的反應爐用於在大面積玻璃基板上 通過化學氣相沉積法生長奈米碳管。其次，該方法採用雷 射光束直接正面照射在奈米碳管生長所需的基底上，由於 雷射場強度較高，容易破壞奈米碳管的生長。 有雲於此’確有必要提供一種改進的雷射辅助化學氣 她積法，其無需在㈣的反應室，且可儘量減少正面照 Φ 射時雷射對奈米碳管生長的破壞。 【發明内容】 種奈米碳管陣列的製備方法，其包括以下步 =提供—基底’在上述基底表面形成—含碳的催化 ^，通人錢氣與賴的混合氣體流經上述催化劑 、面；以及，Μ射光束聚焦_在上述基底表面。 目較於切技術’所述的奈米碳管陣列的製傷方 二=含碳的催化劑層。該催化劑層可有效吸收雷射 此！並加熱催化劑，可削弱雷射場強度，可在一定程 200827471 度上避免雷射破壞新生長出來的奈米碳管，同時在反 應過程中可釋放碳原子促進奈米碳管的成核及生 長。故，本發明實施例奈米碳管陣列的製備方法無需 在一密封的反應室内進行，方法簡單可控。 【實施方式】 下麵將結合附圖對本發明作進一步的詳細說明。 請參閱圖1，本發明實施例奈米碳管陣列的製備方 法主要包括以下幾個步驟： • 步驟一：提供一基底。 本實施例中基底材料選用耐兩溫材料製成。根據 不同應用，本實施例中基底材料還可分別選用不同材 料，如，當應用於半導體電子器件時可選擇為矽、二 氧化矽或金屬材料；當應用于平板顯示器時，優選為 玻璃。基底本身厚度不影響本實施例奈米碳管陣列的 生長，其也可根據實際應用選擇不同厚度。 0 步驟二：在上述基底表面形成一含碳的催化劑層。 本實施例中，該含碳的催化劑層的製備方法包括 以下步驟：提供一種分散劑與一種含碳物質的混合 物，並與一溶劑混合形成溶液；將該溶液進行超聲波 分散處理；在該分散後的溶液中加入金屬硝酸鹽混合 物溶解得到一催化劑溶液；將該催化劑溶液均勻塗敷 於基底表面；烘烤該塗敷有催化劑溶液的基底從而在 基底表面形成一含碳的催化劑層。 其中，該含碳物質包括碳黑或石墨等含碳材料。 200827471 該分散劑用於將含碳物質均勻分散，優選為十二烷基 苯磺酸鈉（Sodium Dodecyl Benzene Sulfonate, SDBS)。溶劑可選擇為乙醇溶液或水。該分散劑與含 碳物質的品質比為1 : 2〜1 : 10，本實施例優選為將 0〜100毫克的十二烷基苯磺酸鈉與100〜500毫克的碳 黑混合物與乙醇溶液混合形成溶液。 該金屬硝酸鹽化合物包括硝酸鎂（Mg(N〇3)2 · 6H2O) 與硝酸鐵（Fe(N〇3)3.9H2〇)、硝酸鈷（Co(N〇3)2.6H2〇)或 硝酸鎳（Ni(N〇3)2 · 6H2O)中任一種或幾種組成的混合 物。本實施例優選為將硝酸鐵（Fe(N〇3)3.9H2〇)與硝酸 鎂（Mg(N〇3V6H2〇)加入到溶液中形成催化劑溶液，該 催化劑溶液中含有0· 01〜〇· 5摩爾（Mo 1/L)的硝酸鎂與 0· 01〜0. 5Mol/L的硝酸鐵。 烘烤的溫度為60〜100°C。烘烤的作用為將催化劑 溶液中的溶劑蒸發從而形成一含碳催化劑層。 本實施例中，該含碳的催化劑層的厚度為1〇〜 微米。催化劑溶液塗敷於基底表面可採用旋轉塗敷的 方式，其轉速為1000〜5000轉/分（rpm)，優選為 1500rpm 〇 本實施例採用上述含碳的催化劑層有以下優點： 第一，該含碳催化劑層可有效吸收雷射能量並加熱催 化劑，.以使得該催化劑層更容易達到生長奈米碳管所 需溫度；第二，該含碳催化劑層可削弱雷射場強度， 可在一定程度上避免雷射破壞新生長出來的奈米碳 200827471 B，第二，該含碳催化劑層在反應過程中可釋放碳原 子促進奈米碳管的成核及生長。 步驟三：通入碳源氣與載氣的混合氣體流經上述 催化劑表面。 該碳源氣優選為廉價氣體乙炔，也可選用其他碳 氫化合物如甲燒、乙烧、乙烯等。載氣氣體優選為氬 氣，也可選用其他惰性氣體如氮氣等。本實施例中， 碳源氣與載氣可通過一氣體喷嘴直接通入到上述催 北劑層表面附近。載氣與碳源氣的通氣流量比例為 5 : W〇 : 1，本實施例優選為通以2〇〇標準毫升/分 (sccm)的氬氣與25sccm的乙炔。 步驟四：以雷射光束聚焦照射在上述基底表面從 而生長奈朱碳管陣列。 本實施例中，雷射光束可通過傳統的氬離子雷射 器或二氧化碳雷射器產生，其功率為0〜5瓦（W)，優 選為470mW。產生的雷射光束可通過一透鏡聚焦後從 正面直接和、射在上述基底表面，可以理解，該雷射光 束可採用垂直照射或傾斜照射聚焦於基底表面的催 化劑層上。 反應預定時間後，由於催化劑的作用，以及雷射 光束照射在基底催化劑層上加熱催化劑，通入到基底 附近的碳源氣在一定溫度下熱解成碳單元（C=C或C) 與氫氣。其中，氫氣會將被氧化的催化劑還原，碳單 元吸附於催化劑層表面，從而生長出奈米碳管。本實 200827471 施例中，由於採用雷射作為加熱熱源，且利用含碳催 化劑層吸收雷射能量的作用，該化學氣相沉積法反應 溫度可低於600攝氏度。 進一步地，由於本發明實施例採用雷射聚焦正面 照射催化劑生長奈米碳管陣列，利用雷射光束照射反 應的碳源氣，從而使氣體能量增加，提高氣體溫度， 可進一步促進碳源氣在較低溫度分解反應生長奈米 碳管陣列。 • 另，由於本發明實施例採用雷射聚焦照射生長奈 米碳管陣列，催化劑局部溫度在較短時間内能夠被加 熱並吸收足夠的能量，同時，碳源氣為直接通入到被 加熱的催化劑表面附近。故，本發明實施例無需一密 封的反應室，即可同時保證生長奈米碳管陣列的催化 劑附近達到所需的溫度及碳源氣的濃度，且，由於碳 源氣分解產生的氫氣的還原作用，可確保氧化的催化 0 劑能夠被還原，並促使奈米碳管陣列生長。 請參閱圖2,本發明實施例依照上述方法以聚焦後 直徑範圍在50〜200微米的雷射光束垂直照射在玻璃 基底的催化劑上約5秒鐘，可得到如圖2所示的奈米 碳管陣列。該奈米碳管陣列為山丘形狀，且垂直於玻 璃基底生長。該奈米碳管陣列的直徑為50〜80微米， 高度為.10〜20微米。每個奈米碳管的直徑為40〜80奈 米。 進一步地，本實施例雷射輔助化學氣相沉積法生 11 200827471 長奈米碳管陣列過程中，可通過控制移動雷射光束掃 描照射在基底的催化劑層上，可實現大面積基底上生 長奈米碳管陣列。 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，自不能以此限制本案之申請專利範圍。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】 圖1係本發明實施例奈米碳管陣列的製造方法的 流程不意圖。 圖2係本發明實施例獲得的奈米碳管陣列的掃描 電鏡照片。 【主要元件符號說明】 益 12200827471 IX. Description of the Invention: [Technical Field] The present invention relates to a method for preparing a carbon nanotube array, and more particularly to a method for preparing a carbon nanotube array by laser assisted chemical vapor deposition. [Prior Art] A new type of one-dimensional nanomaterial discovered only in the early 1990s. The special structure of the carbon nanotubes determines its special properties, such as high wire and high thermal stability. With the change of the carbon nanotube mode, the carbon nanotubes can exhibit metallic or semiconducting properties. Because carbon nanotubes have an ideal one-dimensional structure and excellent properties in the fields of mechanics, electricity, heat, etc., they have shown broad application prospects in the fields of materials science, chemistry, physics, etc., in scientific research and industry. Applications are also receiving more and more attention. The methods for preparing SEM for the preparation of carbon nanotubes mainly include Arc discharge, Laser Ablation, and Chemical Vapor Deposition. Among them, the chemical vapor deposition method has the advantages of high yield, strong controllability, compatibility with the current integrated circuit process, and the like, and is convenient for industrial large-scale synthesis synthesis. attention. The chemical vapor deposition method for preparing carbon nanotubes generally includes the conventional thermal chemical vapor deposition (Therma 1 Chemi ca 1 Vapor Depos iti on, CVD), and the piasma Chemical Vapor Deposition (PCVD). And Laser-Induced Chemical Vapor Deposition (LICVD). 6 200827471 The first laser-assisted chemical vapor deposition method generally uses a laser as a fast heating heat source, and the laser beam is directly irradiated onto the substrate required for growth to raise the temperature to reach the temperature required for growth. When the carbon-containing reaction gas flows through the surface of the high-temperature substrate, it is heated by the substrate, and by reacting with the catalyst on the substrate, the reaction gas generates a pyrolysis or a chemical reaction, thereby realizing the growth of the carbon nanotubes. However, the first laser-assisted chemical vapor deposition method for growing carbon nanotubes has the following disadvantages: First, the method generally needs to be carried out in a sealed reaction furnace, and the reaction gas fills the entire reaction space. The equipment is complicated, and it is difficult to make a large-scale reactor for growing carbon nanotubes by chemical vapor deposition on a large-area glass substrate. Secondly, the method uses a laser beam to directly illuminate the substrate required for the growth of the carbon nanotubes. Due to the high intensity of the laser field, it is easy to destroy the growth of the carbon nanotubes. There is a cloud here. It is indeed necessary to provide an improved laser-assisted chemical gas deposition method, which does not need to be in the reaction chamber of (4), and can minimize the damage of the carbon nanotube growth caused by the frontal illumination. SUMMARY OF THE INVENTION A method for preparing a carbon nanotube array includes the following steps: providing a substrate to form a carbon-containing catalyst on the surface of the substrate, and flowing a mixture of the gas and the gas through the catalyst and the surface. And, the beam is focused _ on the surface of the substrate. The damage of the carbon nanotube array described in the cutting technique is as follows. The catalyst layer absorbs lasers effectively! Heating the catalyst can weaken the intensity of the laser field. It can avoid laser damage to the newly grown carbon nanotubes at a certain degree of 200827471 degrees, and release carbon atoms during the reaction to promote the nucleation and growth of the carbon nanotubes. Therefore, the preparation method of the carbon nanotube array of the embodiment of the invention does not need to be carried out in a sealed reaction chamber, and the method is simple and controllable. [Embodiment] Hereinafter, the present invention will be further described in detail with reference to the accompanying drawings. Referring to FIG. 1, a method for preparing a carbon nanotube array according to an embodiment of the present invention mainly includes the following steps: • Step 1: providing a substrate. In the embodiment, the base material is made of a material resistant to two temperatures. Depending on the application, the substrate material in this embodiment may also be selected from different materials, for example, when used in a semiconductor electronic device, bismuth, germanium dioxide or a metal material; when applied to a flat panel display, glass is preferred. The thickness of the substrate itself does not affect the growth of the carbon nanotube array of this embodiment, and it is also possible to select different thicknesses depending on the actual application. 0 Step 2: Forming a carbon-containing catalyst layer on the surface of the above substrate. In this embodiment, the method for preparing the carbon-containing catalyst layer comprises the steps of: providing a mixture of a dispersing agent and a carbonaceous material, and mixing with a solvent to form a solution; and subjecting the solution to ultrasonic dispersion treatment; after the dispersing The solution of the metal nitrate is added to dissolve the solution to obtain a catalyst solution; the catalyst solution is uniformly applied to the surface of the substrate; and the substrate coated with the catalyst solution is baked to form a carbon-containing catalyst layer on the surface of the substrate. Wherein, the carbonaceous material comprises a carbonaceous material such as carbon black or graphite. 200827471 The dispersant is used to uniformly disperse the carbonaceous material, preferably sodium dodecyl Benzene Sulfonate (SDBS). The solvent can be selected from an ethanol solution or water. The mass ratio of the dispersing agent to the carbonaceous material is 1: 2 to 1: 10, and this embodiment is preferably a mixture of 0 to 100 mg of sodium dodecylbenzenesulfonate and 100 to 500 mg of carbon black and ethanol solution. Mix to form a solution. The metal nitrate compound includes magnesium nitrate (Mg(N〇3)2 · 6H2O) and iron nitrate (Fe(N〇3)3.9H2〇), cobalt nitrate (Co(N〇3)2.6H2〇) or nickel nitrate A mixture of any one or several of (Ni(N〇3)2 · 6H2O). In this embodiment, ferric nitrate (Fe(N〇3)3.9H2〇) and magnesium nitrate (Mg(N〇3V6H2〇) are preferably added to the solution to form a catalyst solution, and the catalyst solution contains 0·01~〇·5 Molar (Mo 1 / L) of magnesium nitrate with 0. 01~0. 5Mol / L of ferric nitrate. Baking temperature is 60 ~ 100 ° C. The role of baking is to evaporate the solvent in the catalyst solution to form a In the present embodiment, the carbon-containing catalyst layer has a thickness of 1 〇 to μm. The catalyst solution is applied to the surface of the substrate by spin coating, and the rotation speed is 1000 to 5000 rpm (rpm). Preferably, it is 1500 rpm. The use of the carbon-containing catalyst layer in the present embodiment has the following advantages: First, the carbon-containing catalyst layer can effectively absorb the laser energy and heat the catalyst, so that the catalyst layer can more easily reach the growth nanometer. The temperature required for the carbon tube; secondly, the carbon-containing catalyst layer can weaken the intensity of the laser field, and can prevent the laser from destroying the newly grown nanocarbon 200827471 B to some extent. Second, the carbon-containing catalyst layer in the reaction process Can release carbon atoms to promote nano The nucleation and growth of the carbon tube. Step 3: a mixed gas of carbon source gas and carrier gas flows through the surface of the catalyst. The carbon source gas is preferably an inexpensive gas acetylene, and other hydrocarbons such as methyl ketone and B may be used. Burning, ethylene, etc. The carrier gas is preferably argon, and other inert gases such as nitrogen may be used. In this embodiment, the carbon source gas and the carrier gas may be directly introduced into the vicinity of the surface of the northmost agent layer through a gas nozzle. The ratio of the aeration flow rate of the carrier gas to the carbon source gas is 5 : W 〇: 1. This embodiment is preferably argon gas of 2 〇〇 standard cc/min (sccm) and acetylene of 25 sccm. Step 4: Laser The light beam is focused on the surface of the substrate to grow a carbon nanotube array. In this embodiment, the laser beam can be generated by a conventional argon ion laser or a carbon dioxide laser, and the power is 0 to 5 watts (W). Preferably, the resulting laser beam is focused by a lens and directly incident on the surface of the substrate from the front surface. It is understood that the laser beam can be focused on the catalyst layer on the surface of the substrate by vertical or oblique illumination. After a predetermined reaction time, the carbon source gas introduced into the vicinity of the substrate is pyrolyzed into a carbon unit (C=C or C) and hydrogen at a certain temperature due to the action of the catalyst and the laser beam is irradiated on the base catalyst layer to heat the catalyst. Among them, hydrogen will reduce the oxidized catalyst, and the carbon unit adsorbs on the surface of the catalyst layer to grow the carbon nanotubes. In the example of 200827471, the laser is used as a heating heat source and absorbed by the carbon-containing catalyst layer. The effect of the laser energy, the chemical vapor deposition reaction temperature may be lower than 600 degrees C. Further, since the embodiment of the present invention uses a laser focused front-illuminated catalyst to grow a carbon nanotube array, the reaction beam is irradiated with a laser beam. The source gas, thereby increasing the gas energy and increasing the gas temperature, further promotes the carbon source gas to decompose at a lower temperature to grow the carbon nanotube array. • In addition, since the embodiment of the present invention uses the laser focused irradiation to grow the carbon nanotube array, the local temperature of the catalyst can be heated and absorbed enough energy in a short time, and at the same time, the carbon source gas is directly passed to the heated Near the surface of the catalyst. Therefore, the embodiment of the present invention can simultaneously ensure that the desired temperature and the concentration of the carbon source gas are reached in the vicinity of the catalyst for growing the carbon nanotube array without a sealed reaction chamber, and the reduction of hydrogen gas due to the decomposition of the carbon source gas. The action ensures that the oxidized catalytic agent can be reduced and promotes the growth of the carbon nanotube array. Referring to FIG. 2, in the embodiment of the present invention, a laser beam having a diameter ranging from 50 to 200 micrometers after focusing is vertically irradiated on the catalyst of the glass substrate for about 5 seconds, thereby obtaining a nanocarbon as shown in FIG. Tube array. The carbon nanotube array is in the shape of a hill and grows perpendicular to the glass substrate. The carbon nanotube array has a diameter of 50 to 80 microns and a height of .10 to 20 microns. Each carbon nanotube has a diameter of 40 to 80 nm. Further, in the laser assisted chemical vapor deposition method of the present embodiment, in the process of the long carbon nanotube array, the laser beam can be scanned and irradiated on the catalyst layer of the substrate to control the growth of the substrate on the large area. Carbon tube array. 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 is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application in this case. Equivalent modifications or variations made by those skilled in the art to the spirit of the invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic flow chart showing a method of manufacturing a carbon nanotube array according to an embodiment of the present invention. Fig. 2 is a scanning electron micrograph of a carbon nanotube array obtained in an embodiment of the present invention. [Main component symbol description] Benefit 12