1. Department of Physics, National Central University 1 , No. 300 Jhongda Road, Jhongli 32054, Taiwan
2. Department of Chemistry, National Taiwan Normal University 2 , No. 88, Sec. 4, Ting-Zhou Road, Taipei, Taiwan
3. National Synchrotron Radiation Research Center 3 , 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan