Growth optimization of double-walled carbon nanotubes yielding precisely designed structures

Abstract

We demonstrate the formation of precisely designed double-walled carbon nanotube (DWNT) structures via growth optimization of thermal chemical vapor deposition. Effects of various growth factors such as different catalyst film-and buffer layer-thicknesses, flow rates and growth time were investigated to produce desired DWNT structures. We used acetylene as the main feedstock and fabricated site selective DWNT vertical structures through a catalyst patterning process. The DWNT structures will be applicable to areas where mechanical stability with thin diameter is required, such as in nanotube-based composites, electron emission devices, heat release components in electric devices and nanoelectromechanical systems.

Length-controlled few-walled carbon nanotubes and their effect on the electrical property of flexible transparent conductive films

“…We deposited a 1-nm-thick Fe layer as a catalytic layer on a 10-nm-thick Al 2 O 3 -covered SiO 2 /Si wafer. The detailed procedure of the CNT growth is described elsewhere [21]. Briefly, the coated substrates were inserted into a quartz tube and heated to 725 • C. Then, the quartz tube was held at this temperature for 10 min, which enabled the formation of catalytic nanoparticles and the achievement of an air annealing effect, which enhances the growth efficiency of CNTs.…”

“…Recently, we reported the controlled growth of a CNT, which mainly consists of triple-walled tubes with a diameter of ∼5 nm [21]. Here, we fabricated TCFs using fewwalled CNTs and report the effect of the length of the CNTs on the electrical property of the films.…”

Investigation of Early Stage of Carbon Nanotube Growth on Plasma-Pretreated Inconel Plates and Comparison with Other Superalloys as Substrates

“…In addition, to grow vertically aligned CNT with quantity, it is essential to deposit a catalytic metal thin films on insulating substrates, such as Al 2 O 3 or SiO 2 . Here, the separation of catalysts and substrates by the buffer layer prevents the formation of alloys or compounds which are harmful for CNT growth [ 14 , 15 ]. On the other hand, it is very difficult to preserve outstanding conductivity at the interface due to the insulating buffer layers.…”