1. Friedrich-Alexander-Universität Erlangen-Nürnberg, Faculty of Engineering, Department of Material Science, Materials for Electronics and Energy Technology (i-MEET), Martensstraße 7, Erlangen 91058, Germany
2. Forschungszentrum Jülich GmbH, Helmholtz-Institut Erlangen-Nürnberg for Renewable Energy (HI ERN), Immerwahrstraße 2, Erlangen 91058, Germany
3. Department of Electric and Mechanical Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan