Probing electrical transport in individual carbon nanotubes and junctions

Journal Article · Tue Jan 01 00:00:00 EST 2008 · Nanotechnology

OSTI ID:941046

Li, An-Ping ^[1]; Kim, Tae Hwan ^[1]; Wendelken, J F ^[1]; Li, Wenzhi ^[1]; Du, Gaohui ^[1]

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1. ORNL

The electrical transport properties of individual carbon nanotubes (CNTs) and multi-terminal junctions of CNTs are investigated with a quadraprobe scanning tunneling microscope. The CNTs are made of herringbone-type stacking graphite sheets with 20 a-angle to the tube axis, and the CNT junctions are free from catalytic particles in the junction areas. The CNTs have a significantly higher resistivity than conventional CNTs with concentric walls. The straight CNTs display linear current-voltage (I-V) characteristics, indicating diffusive transport rather than ballistic transport. The structural deformation in CNTs with bends substantially increases the resistivity in comparison with the straight segments on the same CNTs, and the I-V curve departs slightly from linearity in curved segments. The junction area of the CNT junctions behaves like an ohmic-type scattering center with linear I-V characteristics. In addition, gating effect has not been observed, in contrast to that of conventional multi-walled CNT junctions. These unusual transport properties can be attributed to the enhanced inter-layer interaction in the herringbone-type CNTs.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 941046
• Journal Information: Nanotechnology, Vol. 19, Issue 48
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON
ELECTRIC CONDUCTIVITY
GRAPHITE
NANOTUBES
SEMICONDUCTOR JUNCTIONS