1. Department of Chemistry; Tunghai University; Taichung 407 Taiwan
2. Center of Condensed Matter Science; National Taiwan University; Taipei 106 Taiwan
3. Department of Applied Chemistry; National Chiao Tung University; Hsinchu 300 Taiwan
4. National Synchrotron Radiation Research Center; Hsinchu Science Park; Hsinchu 300 Taiwan
5. Department of Chemical Engineering; National Tsing Hua University; Hsinchu 300 Taiwan
6. Department of Chemistry; National Taiwan University; Center of Condensed Matter Science; National Taiwan University; Taipei 106 Taiwan