1. Division of Physical Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
2. Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
3. Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
4. Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand