1. Department of Physics Basic Science Research Institute and Energy Harvest Storage Research Center University of Ulsan Ulsan 44610 Republic of Korea
2. Convergence Research Institute DGIST Daegu 42988 Republic of Korea
3. School of Electrical and Electronic Engineering Yonsei University Seoul 03722 Republic of Korea
4. Electricity & Electronics and Semiconductor Applications Ulsan College Ulsan 44610 Republic of Korea
5. Department of Physics Kongju National University Kongju 32588 Republic of Korea