1. Department of Materials Science and Engineering National United University Miaoli 36063 Taiwan
2. Taiwan Semiconductor Research Institute Hsinchu 300091 Taiwan
3. Department of Photonics National Cheng Kung University Tainan 701 Taiwan
4. Department of Electronic Engineering National Changhua University of Education Changhua 50074 Taiwan
5. School of Chemistry and Physics and Centre for Materials Science Queensland University of Technology Brisbane QLD 4000 Australia