1. Nanoscience and Technology, Graduate School, Chulalongkorn University, Bangkok, Thailand
2. Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
3. National Electronics and Computer Technology Center (NECTEC), Thailand Science Park, Pathum Thani, Thailand
4. National Metal and Materials Technology Center (MTEC), Thailand Science Park, Pathum Thani, Thailand
5. Department of Advanced Materials Science, The University of Tokyo, Chiba, Japan