1. Institute of Polymer Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
2. Institute of Advanced Materials and Processes (ZMP), Friedrich-Alexander-Universität Erlangen-Nürnberg, 90762 Fürth, Germany
3. School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland
4. Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany