1. Laboratoire de Chimie des Polymères, Faculté des Sciences, Université Libre de Bruxelles (ULB), CP 206/01, Boulevard du Triomphe, 1050 Brussels, Belgium
2. Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 84511 Bratislava, Slovakia
3. Centre for Advanced Materials Application, Dubravska cesta 9, 84511 Bratislava, Slovakia
4. Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria
5. Université de Bordeaux, IMS, CNRS, UMR-5218, Bordeaux INP, ENSCBP, 33405 Talence, France
6. International Solvay Institutes of Physics and Chemistry, ULB, CP 231, Boulevard du Triomphe, 1050 Brussels, Belgium