1. Creative
Research Center for Graphene Electronics, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 305-700, Korea
2. Department
of Physics and Graphene Research Institute, Sejong University, Seoul 143-747, Korea
3. Department
of Physics, Kangwon National University, Kangwon-Do 200-701, Korea
4. Division
of Advanced Materials Engineering, Research Center of Advanced Materials
Development (RCAMD), Chonbuk National University, Jeonju 561-756, Korea
5. Department
of Mechanical Engineering and Texas Center for Superconductivity at
the University of Houston (TcSUH), University of Houston, Houston, Texas 77204-4006, United States
6. Center for
Compound Semiconductors and School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, United States
7. Department
of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Korea