1. Institute for Sustainable Systems Engineering (INATECH), Albert-Ludwigs-University Freiburg, Emmy-Noether-Str. 2, D-79110 Freiburg, Germany
2. Fraunhofer Institute for Applied Solid State Physics, Tullastr. 72, D-79108 Freiburg, Germany
3. Fraunhofer Institute for Mechanics of Materials, Wöhlerstr. 11, D-79108 Freiburg, Germany