中文摘要：

采用射频等离子体增强化学气相沉积技术,以Ni为催化剂,在Si基底上沉积出定向性良好的碳纳米管。用扫描电镜表征了催化剂颗粒大小和相应的碳纳米管形貌。深入研究了催化剂膜厚对碳纳米管生长的影响。结果表明：不同厚度的催化剂薄膜经刻蚀形成的颗粒密度、尺寸、分布等对碳纳米管的合成质量起主要作用。催化剂厚度≤5 nm时,形成的颗粒密度较小而且分布不均,制备的碳纳米管产量低、定向性差。催化剂厚度≥15 nm时,形成的颗粒较大,粘连在一起,生长时大部分被非晶碳包覆,几乎没有碳纳米管的生长。催化剂厚度为10 nm时,形成的颗粒密度大、分布较均,制备的碳纳米管纯度高、定向性好。

英文摘要：

The vertically aligned carbon nanotubes grown on Si substrates with Ni as catalyst were obtained by a technology of radio-frequency plasma enhanced chemical vapor deposition.The size of Ni particles and the surface morphology of carbon nanotubes were characterized by scanning electron microscopy.The effect of catalyst layer thickness on carbon nanotubes has been in depth investigated with the results that the density,size and distribution of Ni catalyst particles formed from catalyst layer of different thickness play a significant role in the surface morphology of carbon nanotubes.When the catalyst thickness is less than 5 nm by plasma etching,the density of catalyst particles are small and unevenly distributed,leading to a low yield and weak orientation of the prepared carbon nanotubes.And,if the thickness is beyond to 15 nm,the catalyst particles are prone to be larger and adhered together.In addition,the most of catalysts are wrapped by amorphous carbon during the process of growth,resulting in a low yield of the carbon nanotubes.However,when the thickness is approximate to 10 nm,the formed catalyst particles are distributed evenly and the density of the particles are large.The produced carbon nanotubes have a high purity and good orientation,compared with synthesized using 5 nm or 15 nm in thickness.