Nonlinear electrical properties of carbon nanotube forests

Abstract

Differential conductance of vertically aligned arrays of multi-walled carbon nanotubes (MWNT forests) reveals a zero bias anomaly at room temperature. The anomaly becomes narrower and sharper upon cooling sample down reaching magnitude of 25% of average conductance at 244 K. Further cooling results in decrease of its magnitude that correlates with the slope of temperature dependence of sample's electrical conductance. The anomaly can be caused by tunneling of charge carriers through nanotube junctions enhanced by temperature gradients induced by measuring currents. Observed phenomenon can be used for the characterization of junction network created by carbon nanotubes in MWNT forests. © 2011 American Institute of Physics.