1. Electronic Materials Research Center Korea Institute of Science and Technology Seoul 02792 Republic of Korea
2. Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA
3. School of Advanced Materials Science and Engineering Sungkyunkwan University Suwon 16419 Republic of Korea
4. Materials Modeling and Characterization Department Korea Institute of Materials Science Changwon 51508 Republic of Korea
5. Division of Nano & Information Technology KIST School University of Science and Technology Daejeon 34113 Republic of Korea