1. BK21 Physics Division, Department of Energy Science, and Center for Nanotubes and Nanostructured Composites, Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University (SKKU), Suwon 440-746, Korea
2. Department of Electrical Engineering and Computer Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
3. Display Lab, Samsung Advanced Institute of Technology (SAIT), P.O. Box 111, Suwon 440-600, Korea
4. Nanomaterials-Processing Group/Energy/Nano Materials Research Center Korea Electronics Technology Institute (KETI) 68 Yatap-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-816, Korea