Non-ohmic current-voltage characteristics in single-wall carbon nanotube network

The non-ohmic current-voltage (I-V) characteristics of the single-wall carb on nanotube network were investigated at low temperatures. The temperature dependence of resistivity at low current (I < 10 <mu>A) shows non-metallic negative d rho /dT from T = 1.4-300 K. Below T < 15 K, gradual decreases of resistivity are observed as the applied currents increase, showing signifi cant non-ohmic behavior at high electric field. The I-V curves in the non-o hmic regime can be fitted well by the fluctuation-induced tunneling model, indicating the importance of inter-tubular contacts or inherent energy barr iers inside the tubes. (C) 2001 Elsevier Science B.V. All rights reserved.