Non-Ohmic behavior of carrier transport in highly disordered graphene

Shun-Tsung Lo, Chiashain Chuang, R. K. Puddy, T. -M. Chen, C. G. Smith, C. -T. Liang

Published 2013-10-23, updated 2013-10-26Version 2

We report measurements of disordered graphene probed by both a high electric field and a high magnetic field. By apply a high source-drain voltage Vsd, we are able to study the current-voltage relation I-Vsd of our device. With increasing Vsd, a crossover from the linear I-Vsd regime to the non-linear one, and eventually to activationless-hopping transport occurs. In the activationless-hopping regime, the importance of Coulomb interactions between charged carriers is demonstrated. Moreover, we show that delocalization of carriers which are strongly localized at low T and at small Vsd occurs with the presence of high electric field and perpendicular magnetic field..