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碳纳米管的生长通常使用Fe,Co,Ni作为催化剂,除此以外的一些过渡元素也能催化裂解生长碳管。其中用铜制备的碳管阈值电场低、发射电流密度大、发射均匀性好等等良好的场发射特性。铜与硅、或金属之间具有很强的的扩散特性,而碳管应用于场发射显示器必然使用玻璃、硅片作为衬底,所以需要一层缓冲层阻挡催化剂铜扩散入衬底。本文使用磁控溅射制备铜薄膜作为催化剂,化学气相沉积方法裂解乙炔生长碳管薄膜形成场发射阴极。并试验W,Ni,Cr和Ti作为铜薄膜的缓冲层,结果表明不同的金属阻挡特性不同,生长后碳管的形貌和特性都有差异。结果表明Ti和W能很好地阻挡铜的扩散,从而使铜催化裂解出附着性好、分布均匀、密度适中、场发射特性良好的碳管薄膜。对于Ni和Cr金属,由于生长的碳管与衬底结合差或者场发射能力差而不适合作铜的缓冲层。
The growth of carbon nanotubes usually uses Fe, Co and Ni as catalysts, and some other transition elements can also catalytically crack growth carbon nanotubes. Among them, the carbon nanotubes prepared by copper have low threshold electric field, high emission current density, good emission uniformity and so on. Copper and silicon, or metal with strong diffusion characteristics, and carbon nanotubes used in field emission displays inevitably use glass, silicon as a substrate, so the need for a buffer layer to stop the catalyst copper diffusion into the substrate. In this paper, magnetron sputtering was used to prepare copper thin film as a catalyst, and chemical vapor deposition was used to crack the carbon nanotube film to form the field emission cathode. W, Ni, Cr and Ti were tested as the buffer layer of the copper thin film. The results show that the barrier properties of different metals are different, and the morphology and properties of the carbon nanotubes after the growth are different. The results show that Ti and W can well block the diffusion of copper, so that the copper catalyst cracked good adhesion, uniform distribution, moderate density, good field emission characteristics of the carbon nanotube film. For Ni and Cr metals, copper tubes are not suitable as copper buffer due to their poor bonding to the substrate or poor field emission.