1. Department of Materials, Department of Physics and Molecular, Cellular & Developmental Biology Department; University of California at Santa Barbara; CA USA
2. Institute of Physics; Academia Sinica; Taipei Taiwan
3. National Synchrotron Radiation Research Center; Hsinchu Taiwan
4. Department of Electrophysics; National Chiao-Tung University; Hsinchu Taiwan
5. Department of Materials Science and Engineering; University of Illinois; Urbana IL USA