1. Research & Development Group, Hitachi, Ltd., Yokohama 244-0817, Kanagawa, Japan
2. Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan
3. State Key Laboratory of Physical Chemistry of Solid Surface, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
4. Department of Optical Science and Technology, Faculty of Engineering, Tokushima University, Tokushima 770-8501, Japan
5. School of Engineering, Tokai University, Hiratsuka 259-1292, Kanagawa, Japan