1. Department of Physics, Faculty of Science and Technology, Thammasat University, Pathumthani 12121, Thailand
2. Research Unit in Innovative Sensors and Nanoelectronic Devices, Thammasat University, Pathumthani 12121, Thailand
3. Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
4. School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Korea