1. Institut Photovoltaïque d’Île-de-France (IPVF), 91120 Palaiseau, France
2. CNRS, Institut Photovoltaı̈que d'Île de France (IPVF), UMR 9006, 91120 Palaiseau, France
3. National Center for Photovoltaics, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
4. Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
5. Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, United States