1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
2. School of Chemistry
and Biochemistry
and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400,
United States
3. School of
Materials Science and
Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
4. Physics Department, Moscow State University, Moscow, Russia