1. Department of Physics, Sogang University, Seoul 121-742, South Korea
2. Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan
3. Department of Electrical and Electronic Engineering, University of Miyazaki, Miyazaki 889-2192, Japan
4. Korea Center for Artificial Photosynthesis, Center for Microcrystal Assembly, Department of Chemistry, Sogang University, Seoul 121-742, South Korea