Studies on large area and low temperature fabrication and reaction dynamics of aligned carbon nanostructures

开展了垂直定向碳纳米结构的制备，并成功地制备了新型垂直定向碳纳米结构。1.碳纳米管的制备利用电容耦合等离子体射频等离子体增强化学气相沉积技术制备了二维碳纳米结构(碳纳米管：CNWs)。在没有注入氢自由基的情况下，没有制备出碳纳米管。碳纳米管的形态取决于碳源气体(C2F6、CF4、CHF3a、CH4等)的类型。碳纳米管是在无催化剂的情况下在硅、二氧化硅和不锈钢衬底上生长的，与衬底材料无关。2.采用微波等离子体增强化学气相沉积法制备了致密碳纳米管碳纳米管。采用准分子激光烧蚀法制备了纳米CO催化剂。通过改变钴催化纳米粒子的沉积时间，可以控制直径约为6 nm的碳纳米管的密度。在生长的前3min，碳纳米管生长迅速，随后生长速度明显减慢。在生长初期，碳纳米管以300 nm/s的极高速率生长。3.利用常压等离子体生长碳纳米管研制了一种微波激励的非平衡大气压等离子体源，并将其应用于化学气相沉积碳纳米管。以He/H2/CH4和He/H2/CF4为原料，在600℃的低温下成功地合成了多壁碳纳米管。

The investigation shown in the following as the fabrication of the vertically aligned carbon nanostructures has been carried out, and it succeeded in the creation of the novel vertically aligned carbon nanostructures.1.Fabrication of carbon nanowalls (CNWs)Two-dimensional carbon nanostructures (carbon nanowalls : CNWs) were fabricated using capacitively coupled plasma radio-frequency plasma-enhanced chemical vapor deposition assisted by H radical injection. In the case of the deposition without H radical injection, CNWs were not fabricated. The morphologies of CNWs were dependent on the types of carbon source gases (C_2F_6,CF_4,CHF_3a,CH_4,etc). CNWs were grown on Si,SiO_2, and stainless steel substrates without catalyst, and independent of substrate materials. It succeeded the fabrication of the CNWs with stripe structure by tilting the substrates.2.Dense carbon nanotubesCarbon nanotubes (CNTs) were synthesized using microwave plasma-enhanced chemical vapor deposition. Co nanoparticles as catalyst were prepared using excimer laser ablation. The density of CNTs with a diameter of approximately 6 nm was controllable by changing the deposition time of Co catalytic nanoparticles. CNTs were grown rapidly during the first 3min of growth, then the growth rate of CNTs decreased markedly. At early stage of growth, the CNTs grew at an extremely high rate of 300 nm/s.3.Growth of carbon nanotubes by atmospheric-pressure plasmaA microwave excited non-equilibrium atmospheric pressure plasma source was developed and applied to chemical vapor deposition of carbon nanotubes (CNTs). Multiwalled CNTs were successfully synthesized at a low temperature of 600℃ by using mixtures of He/H_2/CH_4 and He/H_2/CF_4.