1. Department
of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang
Mai 50202, Thailand
2. Nanoelectronics
and MEMS Laboratory, National Electronics and Computer Technology
Center, National Science and Technology Development Agency, Klong Luang, Pathumthani 12120, Thailand
3. Materials
Science Research Center, Faculty of Science, Chiang Mai University, Chiang
Mai 50202, Thailand