1. Department of Physics, National Chung Hsing University, Taichung 402, Taiwan
2. Institute of Nanoscience, National Chung Hsing University, Taichung 402, Taiwan
3. Brightek Optoelectronic Co., LTD, Taoyuan City 330, Taiwan
4. Innovation and Development Center of Sustainable Agriculture (IDSCA), Taichung 402, Taiwan