1. Department of Advanced Convergence Technology and Research Institute for Advanced Convergence Technology, Korea Polytechnic University, Siheung-Si 15073, Republic of Korea
2. Department of Physics, Yonsei University, Wonju-Si 26493, Republic of Korea
3. School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
4. Korea Evaluation Institute of Industrial Technology, Daegu 41069, Republic of Korea