1. Department of Materials Science and Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 10607, Taiwan
2. Institute of Polymer Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617 Taiwan
3. National Synchrotron Radiation Research Center (NSRRC), Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
4. Center for Condensed Matter Sciences, National Taiwan University, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
5. Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan