1. Leibniz Institute of Photonic Technology, Albert-Einstein Strasse 9, 07745 Jena, Germany
2. Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, D-07743 Jena, Germany
3. School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
4. Department of Chemistry, National Tsing Hua University, 101 Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
5. Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
6. Research Center for Applied Sciences, Academia Sinica, 128 Sec. 2, Academia Road, Nankang District, Taipei 11529, Taiwan
7. Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan