1. KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
2. Department of Physics, Graphene Research Institute, and GRI-TPC International Research Center, Sejong University, Seoul 05006, Republic of Korea
3. School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 44919, Republic of Korea
4. Department of Physics, Korea University, Seoul 02841, Republic of Korea
5. UNIST Central Research Facilities (UCRF), Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 44919, Republic of Korea
6. Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
7. Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul 08826, Republic of Korea
8. Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea
9. Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea