等离子体对低温定向生长碳纳米管的作用

Effect of Plasma on Orientation Growth of Carbon Nanotubes at Low Temperature

利用负偏压增强热丝化学气相沉积在低衬底温度(550℃)下催化生长了碳纳米管,并用扫描电子显微镜研究了它的生长过程,发现低温下碳纳米管能否定向生长依赖于等离子体功率,同时还发现碳纳米管在压强太低时不能够生长。结合有关理论分析,结果表明,当等离子体功率较大时,等离子体形成的强电场对催化剂颗粒的作用导致了碳纳米管的定向生长;而低压下碳纳米管不能够生长是由于碳粒子扩散太快的缘故。

Carbon nanotubes were catalytically grown by negative bias-enhanced hot filament chemical vapor deposition at low substrate temperature （550 ℃） and their growth was investigated by scanning electron microscopy. It is found whether the carbon nanotubes could be orientationally grown at low temperature depended on the plasma power and carbon nanotubes could not be grown if the pressure was too low. The analysis results by the related theory indicate that the interaction of the strong electrical field formed by plasma with the catalyst particles resulted in the orientation growth of carbon nanotubes when the plasma power was large and the diffusion of the particles containing carbon at low pressure was too fast to grow the carbon nanotubes.