1. Institute of Physics and AstronomyUniversity of Potsdam Potsdam 14476 Germany
2. Young Investigator Group Perovskite Tandem Solar CellsHelmholtz‐Zentrum Berlin für Materialien und Energie GmbH Berlin 12489 Germany
3. Department of PhysicsSwansea University Singleton Park Swansea Wales SA2 8PP UK
4. Institute for Silicon PhotovoltaicsHelmholtz‐Zentrum Berlin für Materialien und Energie GmbH Berlin 12489 Germany
5. Faculty IV – Electrical Engineering and Computer Science TechnicalUniversity Berlin Berlin 10587 Germany