1Graduate
School of Nanoscience and Technology (GSNT) and Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
2Nano-Convergence
Systems Research Division, Korea Institute of Machinery and Materials (KIMM), Daejeon 34103, Republic of Korea
3Department
of Chemistry, Hanoi Pedagogical University No2, Vinh Phuc, Vietnam
4Department of Nanomechatronics, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea