1. Institute of Energy and Climate Research IEK-5 Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich Germany
2. Faculty of Electrical Engineering and Information Technology RWTH Aachen University 52062 Aachen Germany
3. Institute of Energy and Climate Research IEK-9 Fundamental Electrochemistry Forschungszentrum Jülich GmbH 52425 Jülich Germany
4. Forschungszentrum Jülich Helmholtz Institute Münster 48149 Jülich Germany