1. Department of Electro-Optical Engineering, Minghsin University of Science and Technology, Hsinchu, Taiwan
2. Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou, Taiwan
3. Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
4. Department of Energy and Refrigerating Air Conditioning Engineering, National Taipei University of Technology, Taipei, Taiwan
5. Department of Electrical Engineering, Yale University, New Haven, CT, USA