1. Institute of Microelectronics & Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan
2. Optical Science Center, National Central University, Chung‐Li 32054, Taiwan
3. South Epitaxy Corporation, Hsin‐Shi 744, Taiwan
4. Department of Electrical Engineering, Kun‐Shan University of Technology, Yung‐Kang 710, Taiwan
5. Department of Mechanical Engineering, Southern Taiwan University of Technology, Yung‐Kang 710, Taiwan