1. Material
Research Center, Samsung Advanced Institute of Technology, Suwon, Gyeonggi-do 443-803, Korea
2. Department
of Graphic Arts Information Engineering, Pukyong National University, Busan 608-739, Korea
3. Laboratory
for Solid State Physics, ETH Zurich, Zurich 8093, Switzerland
4. Photo-Electronic
Hybrids Research Center, Korea Institute of Science and Technology, Seoul 136-791, Korea
5. KU-KIST
Graduate School of Converging Science and Technology, Korea University, Seoul 136-701, Korea