1. Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
2. Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan
3. Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan, Republic of China
4. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, Republic of China
5. Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan 30010, Republic of China