1. The MacDiarmid
Institute for
Advanced Materials and Nanotechnology, Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch
8140, New Zealand
2. Department
of Solid State Physics,
Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Lodz, Poland
3. Department of Physics, University of Illinois at Urbana−Champaign,
1110 West Green Street, Urbana, Illinois 61801-3080, United States
4. College of Science, Nanjing University of Science and Technology, Nanjing
210094, China