1. Materials Science and Nanotechnology Program, Faculty of Science; Khon Kaen University; Khon Kaen 40002 Thailand
2. Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science; Khon Kaen University; Khon Kaen 40002 Thailand
3. Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage; Khon Kaen University; Khon Kaen 40002 Thailand
4. Graduate School of Engineering; Osaka University; 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
5. JST; PRESTO; 4-1-8 Honcho Kawaguchi Saitama 332-0012 Japan