1. Department of Applied Physics, University of Tsukuba, Ibaraki 305-8577, Japan
2. Alliance for Research on the Mediterranean and North Africa (ARENA), University of Tsukuba, Ibaraki 305-8577, Japan
3. Department of Chemistry, Konan University, Kobe 658-8501, Japan
4. Research Center for Solar Energy Chemistry, Osaka University, Osaka 565-0871, Japan
5. Tokyo Instruments, Inc., Tokyo 134-0088, Japan
6. Department of Materials Chemistry, Ryukoku University, Shiga 520-2194, Japan