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Journal of Nanomaterials
Volume 2015, Article ID 917637, 9 pages
http://dx.doi.org/10.1155/2015/917637
Research Article

Density Functional Investigation of Graphene Doped with Amine-Based Organic Molecules

1Department of Chemistry, Chung-Ang University, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756, Republic of Korea
2School of Food Science and Technology, Chung-Ang University, Ansung, Gyeonggi 456-756, Republic of Korea
3Department of Chemistry, Kunsan National University, Gunsan, Jeollabuk-do 573-701, Republic of Korea

Received 7 June 2015; Accepted 2 July 2015

Academic Editor: Jin W. Seo

Copyright © 2015 Yeun Hee Hwang 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.

Abstract

To improve the electronic properties of graphene, many doping techniques have been studied. Herein, we investigate the electronic and molecular structure of doped graphene using density functional theory, and we report the effects of amine-based benzene dopants adsorbed on graphene. Density functional theory (DFT) calculations were performed to determine the role of amine-based aromatic compounds in graphene doping. These organic molecules bind to graphene through long-range interactions such as π-π interactions and C-H⋯π hydrogen bonding. We compared the electronic structures of pristine graphene and doped graphene to understand the electronic structure of doped graphene at the molecular level. Also, work functions of doped graphene were obtained from electrostatic potential calculations. A decrease in the work function was observed when the amine-based organic compounds were adsorbed onto graphene. Because these systems are based on physisorption, there was no obvious band structure change at point K at the Fermi level after doping. However, the amine-based organic dopants did change the absolute Fermi energy levels. In this study, we showed that the Fermi levels of the doped graphene were affected by the HOMO energy level of the dopants and by the intermolecular charge transfer between the adsorbed molecules and graphene.