Affiliation: | 1. NCRI, Center for Smart Molecular Memory, Department of Chemistry, Samsung‐SKKU Graphene Center, Sungkyunkwan University, Suwon 440‐746, Republic of Korea, Fax: (+82) 31‐299‐5934, Homepage: http://home.skku.edu/~hyoyoung;2. SKKU Advanced Institute of Nano Technology(SAINT), Sungkyunkwan University, Suwon 440‐746, Republic of Korea |