We report an electron transport study of lithographically fabricated graphene nanoribbons of various widths and lengths at different temperatures. At the charge neutrality point, a length-independent transport gap forms whose size is inversely proportional to the width. In this gap, electron is localized, and charge transport exhibits a transition between simple thermally activated behavior at higher temperatures and a variable range hopping at lower temperatures. By varying the geometric capacitance through the addition of top gates, we find that charging effects constitute a significant portion of the activation energy.
@article{arxiv.0910.4808,
title = {Electron Transport in Disordered Graphene Nanoribbons},
author = {Melinda Y. Han and Juliana C. Brant and Philip Kim},
journal= {arXiv preprint arXiv:0910.4808},
year = {2015}
}