1. School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
2. School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
3. National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Pathum Thani 12120, Thailand