1. Faculty of Science; Department of Physics; Khon Kaen University; 123 Mittraphap Rd. Muang Khon Kaen 40002 Thailand
2. Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage; Khon Kaen 40002 Thailand
3. Integrated Nanotechnology Research Center; Khon Kaen University; Khon Kaen 40002 Thailand
4. Faculty of Science; Department of Physics; Chulalongkorn University; Phayathai Rd. Patumwan Bangkok 10330 Thailand
5. Department of Physics, Chemistry, and Biology (IFM); Linköping University; 58183 Linköping Sweden
6. Department of Advanced Materials Science; The University of Tokyo; 5-1-5 Kashiwanoha Kashiwa Chiba 277-8561 Japan