1. Department of Organic Materials and Fiber Engineering
2. Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 120-749, Republic of Korea
3. Department of Physics
4. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
5. Pohang Accelerator Laboratory, POSTECH, Pohang 790-784, Korea
6. Display Device & Materials Laboratory, Samsung Advanced Institute of Technology, Yongin, 446-712, Republic of Korea