1. Graduate Institute of Photonics and Optoelectronics Department of Electrical Engineering National Taiwan University (NTU) No. 1, Sec. 4, Roosevelt Road Taipei 10617 Taiwan
2. Program on Key Materials Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan 70101 Taiwan
3. Department of Photonics National Cheng Kung University Tainan 70101 Taiwan
4. Institute for Materials Chemistry and Engineering (IMCE) Kyushu University 744 Motooka Nishiku Fukuoka 819‐0395 Japan
5. Advanced Institute for Materials Research (AIMR) Tohoku University Sendai 980‐8577 Japan