Structure-Dependent Electrical Properties of Carbon Nanotube Fibers

The electron transport properties of neat, well-aligned carbon nanotubes (CNT) fibers spun from arrays of millimeter-long CNTs were reported. The electric resistance of CNT fibers at temperatures from 300 K to 75.4 K investigated the electronic properties of as-spun fibers and their possible conducting mechanisms. The results show that CNTs align well in the spun fibers and have good CNT alignment and high purity. The longer CNTs have lower contact resistance as they have fewer end connections and larger contact area between neighboring tubes. The two-terminal current-voltage (I-V) characteristics of a spun CNT fiber indicate a linear nature of the I-V curves, which reveals good ohmic contacts between the CNT fibers and the electrodes. The dependence of conductivity of CNT fibers on their structures is due to the variation in carrier density and π-bonding system of CNTs caused by different chemical treatments.