1. Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan
2. Green Energy & Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan
3. Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan
4. Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan