1. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
2. Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
3. Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
4. Institute of Biophotonics, National Yang Ming University, Taipei 112, Taiwan
5. Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan