Synthesis And Characterization Of Well-Aligned Carbon Nanotubes And Boron-doped Carbon Nanotubes By ECR-CVD

The large area well-aligned carbon nanotube (CNT) arrays were synthesized on porous silicon by electron cyclotron resonance chemical vapor deposition (ECR-CVD) with CH4 and H2 as the source gases, Fe3O4 nanoparticle as the catalyst and without applying electrical field. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD) and energy dispersive X-ray analysis (EDX) were used to evaluate the structure and composition. The result showed the CNTs have outer diameters of about 60～90 nm and length of 8μm and showed straight tubular and chain structures.The effects of process parameters such as gas composition, working pressure, temperature and deposition time for CNTs growing characteristics were investigated. The result shows that the gas composition and working pressure influence the concentration of carbon radical in the chamber, which may influence growth rate, density and aligned growth of CNTs; The temperature controls the diameters of CNTs by changing the size of catalyst but CNTs can't tend to aligned growth at lower temperature; First, CNTs become longer and longer according to the deposition time, but they stop growing after a certain time.The influence of different catalyst and substrate were studied. Fe3O4 nanoparticle, Co nanoparticle and Fe(NO)3 sol were used as catalyst and porous silicon, Si (111) and quartz were used as substrates, respectively. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) were used to evaluate the morphology and structure. The results show that the catalyst affects the density and growth rate, the substrate affects the morphology and growth mode by controlling the characteristic and distributing uniformity of catalyst. Well-aligned carbon nanotubes were synthesized on porous silicon with Fe3O4 nanoparticle as catalyst in the present study.Boron-doped carbon nanotubes (CNTs) have been synthesized on porous silicon by ECR-CVD. CH4,B2H6 and H2 were used as the source gases and Fe3O4 nanoparticle as the catalyst. The effects of gas composition for boron-doped CNTs growing characteristics were...