920 resultados para Functionalized Carbon Nanotubes
Resumo:
Plasma enhanced chemical vapour deposition (PECVD) is a controlled technique for the production of vertically aligned multiwall carbon nanotubes for field emission applications. In this paper, we investigate the electrical properties of individual carbon nanotubes which is important for designing field emission devices. PECVD nanotubes exhibit a room temperature resistance of 1-10 kΩ/μm length (resistivity 10-6 to 10-5 Ω m) and have a maximum current carrying capability of 0.2-2 mA (current density 107-108 A/cm2). The field emission characteristics show that the field enhancement of the structures is strongly related to the geometry (height/radius) of the structures and maximum emission currents of ∼ 10 μA were obtained. The failure of nanotubes under field emission is also discussed. © 2002 Elsevier Science B.V. All rights reserved.
Resumo:
We have fabricated self-aligned, side-gated suspended multi-walled carbon nanotubes (MWCNTs), with nanotube-to-gate spacing of less than 10 nm. Evaporated metal forms an island on a suspended MWCNT, the island and the nanotube act as a mask shielding the substrate, and lift-off then removes the metal island, leaving a set of self-aligned side gates. Al, Cr, Au, and Ti were investigated and the best results were obtained with Cr, at a yield of over 90%.
Resumo:
We describe the fabrication of self-aligned split gate electrodes on suspended multiwalled carbon nanotube structures. A suspended multiwalled carbon nanotube structure was used as an evaporation mask for the deposition of metal electrodes resulting in the formation of discontinuous wire deposition. The metal deposits on the nanotubes are removed with lift-off due to the poor adhesion of metal to the nanotube surface. Using Al sacrificial layers, it was possible to fabricate self-aligned contact electrodes and control electrodes nanometers from the suspended carbon nanotubes with a single lithography step. It was also shown that the fabrication technique may also be used to form nano-gaped contact electrodes. The technique should prove useful for the fabrication of nano-electromechanical systems.
Resumo:
We describe the fabrication of self-aligned split gate electrodes on suspended multiwalled carbon nanotube structures. A suspended multiwalled carbon nanotube structure was used as an evaporation mask for the deposition of metal electrodes resulting in the formation of discontinuous wire deposition. The metal deposits on the nanotubes are removed with lift-off due to the poor adhesion of metal to the nanotube surface. Using Al sacrificial layers, it was possible to fabricate self-aligned contact electrodes and control electrodes nanometers from the suspended carbon nanotubes with a single lithography step. It was also shown that the fabrication technique may also be used to form nano-gaped contact electrodes. The technique should prove useful for the fabrication of nano-electromechanical systems. © 2003 Materials Research Society.
Resumo:
The numerical solutions of or(R) given by two different methods (Samsonov et al., 2003; and Lu et al., 2005) are compared with the result that they are coincident closely (the difference is within 4%). We conclude that it is necessary to consider the Tolman correction in the calculation of fluid dynamics in carbon nanotubes. Although our conclusion is the same as that of Prylutskyy et al. (2005), the sign of our Tolman correction is opposite to theirs, and the difference can be attributed to the errors appeared in the paper of Prylutskyy et al.