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Journal of Nanomaterials
Volume 2016, Article ID 7372812, 4 pages
Research Article

Charge Trapping in Monolayer and Multilayer Epitaxial Graphene

1Graduate Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan
2International Center for Quantum Materials, Peking University, Beijing 100871, China
3Department of Physics, National Taiwan University, Taipei 106, Taiwan
4Graduate School of Advanced Integration Science, Chiba University, Chiba 263-8522, Japan
5National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA

Received 11 December 2015; Accepted 10 March 2016

Academic Editor: Ungyu Paik

Copyright © 2016 Chieh-I Liu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We have studied the carrier densities of multilayer and monolayer epitaxial graphene devices over a wide range of temperatures . It is found that, in the high temperature regime (typically T ≥ 200 K), shows a linear dependence of 1/T, showing activated behavior. Such results yield activation energies for charge trapping in epitaxial graphene ranging from 196 meV to 34 meV. We find that decreases with increasing mobility. Vacuum annealing experiments suggest that both adsorbates on EG and the SiC/graphene interface play a role in charge trapping in EG devices.