1. School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
2. Sydney Nano, The University of Sydney, Sydney, New South Wales 2006, Australia
3. ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
4. ARC Centre of Excellence in Exciton Science, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia
5. Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
6. Advanced Research Center for Green Materials Science and Technology, National Taiwan University, Taipei 106, Taiwan
7. Instrumentation Center, National Taiwan University, Taipei 106, Taiwan
8. Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan
9. ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, Victoria 3001, Australia
10. School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia