As one of the most promising candidate material for next generation electronic devices,the reliable and controllable synthesis of high quality single-walled carbon nanotubes(SWNTs) has long been an essential and important issue in the field.Direct growth of SWNTs on flat substrates by chemical vapor deposition(CVD) process is the best way to obtain SWNTs because it is immediately ready for building nano-devices.The orientation of the SWNTs has been well controlled by gas flow or substrate lattice during the CVD growth process.The chirality and structure control of SWNTs is still a big challenge.However,the conductivity selective growth has already partially succeeded.New catalysts have been explored to obtain SWNTs of higher quality.Along with the further progress in the study of the SWNT growth,the precise control over the orientation,position and conductivity of SWNTs is expected to meet the requirements of carbon-based nanoelectronics.
PENG FeiLIU YuCUI RongLiGAO DongLiangYANG FengLI Yan
Molecular nanoclusters containing Fe and Mo atoms have been used as catalyst precursors for the growth of single-walled carbon nanotubes (SWNTs) on stable temperature (ST)-cut quartz substrates by chemical vapor deposition. Attribute to the uniform catalyst nanoparticles and the confinement effect of the crystalline substrates, well-aligned SWNTs with narrow diameter distribution have been synthesized. Atomic force microscopy measurements show that the mean diameter of the nanotubes obtained by thermal decomposition of ethanol at 900°C is 0.76 ± 0.16 nm, which is the smallest among all reported results for aligned SWNTs. The mean diameter of the nanotubes increases with growth temperature. In addition to using identical nanoclusters as the catalyst precursors, the avoidance of annealing treatment of catalyst precursors is also a key point for obtaining SWNTs with controlled diameters. Using these identical nanoclusters as catalyst precursors and carefully tuning the growth parameters make us closer to the ultimate goal of controlling the chirality of SWNTs.
PENG FeiLUO DaSUN HaoWANG JinYongYANG FengLI RuoMingYANG JuanLI Yan
