Influence of structural and dielectric anisotropy on the dielectrophoresis of single-walled carbon nanotubes.
We report on a carbon nanotube network which is composed of aligned metallic and randomly oriented semiconducting single-walled carbon nanotubes. The material is formed by using a novel radio frequency dielectrophoresis setup, which generates very large dielectrophoretic force fields and allows dielectrophoretic assembling of nanotube films up to 100 nm thickness. Polarization dependent absorption measurements provide experimental evidence for the electronic type specific alignment behavior. We explain the experimental data with an advanced model for nanotube dielectrophoresis, which explicitly takes into account both the longitudinal and transversal polarizability. On the basis of this model, we calculate the dielectrophoretic force fields and show that semiconducting nanotubes deposit under very large fields due to their transversal polarizability even for high field frequencies.
Blatt
Sabine
S
Institut für Nanotechnologie, Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany. blatt@int.fzk.de
Hennrich
Frank
F
Löhneysen
Hilbert V
HV
Kappes
Manfred M
MM
Vijayaraghavan
Aravind
A
Krupke
Ralph
R
D016880:Anisotropy; D004581:Electronics; D004586:Electrophoresis; D008956:Models, Chemical; D037742:Nanotubes, Carbon / Q000737:chemistry; D012666:Semiconductors
D037742:Nanotubes, Carbon