1. Karlsruhe Institute of TechnologyLight Technology Institute (LTI) Engesserstrasse 13 76131 Karlsruhe Germany
2. Karlsruhe Institute of TechnologyMaterial Research Center for Energy Systems (MZE) Strasse am Forum 7 76131 Karlsruhe Germany
3. Karlsruhe Institute of TechnologyInstitute for Applied Materials–Ceramic Materials and Technologies (IAM) Haid‐und‐Neu‐Strasse 7 76131 Karlsruhe Germany