Anisotropic electrical transport properties of aligned carbon nanotube films

Citation
Xb. Wang et al., Anisotropic electrical transport properties of aligned carbon nanotube films, J PHYS CH B, 105(39), 2001, pp. 9422-9425
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHYSICAL CHEMISTRY B
ISSN journal
1520-6106 → ACNP
Volume
105
Issue
39
Year of publication
2001
Pages
9422 - 9425
Database
ISI
SICI code
1520-6106(20011004)105:39<9422:AETPOA>2.0.ZU;2-F
Abstract
We report a large scale synthesis of well-aligned carbon nanotube films wit h controllable diameter and length. A simple technique has been developed t o measure anisotropic electrical transport properties of as-aligned carbon nanotube films. The temperature dependence of relative electrical resistanc es suggests that most of the well-aligned carbon nanotubes are semiconducti ve in both directions parallel and perpendicular to the tube axis. The anis otropy (R-perpendicular to/R-parallel to) of electrical resistances increas es with decreasing temperature T, reflecting difference in the longitudinal and transverse hopping rates. The differences of the electrical properties in both directions could be explained by a difference in the degree of loc alization of charge carries. The plot of the logarithm of relative resistan ce against powers of the reciprocal temperature 1/T is closely fitted by th ree-dimensional variable range conduction. After annealing and Br-2-doping treatments, the resistivities of the aligned carbon nanotube films decrease d by 2 orders of magnitude, which resulted from fewer defects and more carr ies density, respectively.