1. Institute of Nuclear Energy Research, Longtan, Taoyuan 32546, Taiwan
2. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
3. Department of Electronic Engineering, Minghsin University of Science and Technology, Hsinchu 30401, Taiwan
4. Department of Materials Engineering, Ming-Chi University of Technology, New Taipei City 24301, Taiwan
5. Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan