1. Thomas J. Watson Research Center; IBM Research; 1101 Kitchawan Road, Yorktown Heights, NY 10598 USA
2. CNRS; Institut Photovoltaïque Ile de France (IPVF); 30 route départementale 128 91120 Palaiseau France
3. EDF Recherche et Développement; Institut Photovoltaïque Ile de France; 30 route 128 91120 Palaiseau France