1. SKKU Advanced Institute of Nano-Technology (SAINT), Samsung-SKKU Graphene Center, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea
2. Graphene Center, Samsung Advanced Institute of Technology, San 14, Nongseo-dong, Giheung-gu, Yongin, Gyeonggi-do 446-712, Korea