1. Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
2. Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand
3. Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
4. Institute of Nanomaterials Research and Innovation for Energy (IN-RIE), NANOTEC-KKU RNN on Nanomaterials Research and Innovation for Energy, Khon Kaen University, Khon Kaen, Thailand