1. Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 Bern CH‐3012 Switzerland
2. Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics Technical University of Dresden Nöthnitzerstrasse 61 D‐01187 Dresden Germany
3. Department of Chemistry Technical University of Munich Lichtenbergstrasse 4 D‐85748 Garching b. München Germany
4. Center for Advancing Electronics Dresden Technical University of Dresden Helmholtzstrasse 18 D‐01069 Dresden Germany
5. IBM Almaden Research Center 650 Harry Road San Jose CA 95120 USA
6. Leibniz Institute of Polymer Research Dresden Hohestrasse 6 D‐01069 Dresden Germany