1. Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
2. it4ip s.a., Avenue Jean-Etienne Lenoir 1, B-1348 Louvain-la-Neuve, Belgium
3. R&D Center for Materials and Electronic & Optoelectronic Devices (MDEO), Faculty of Physics, University of Bucharest, 077125 Măgurele, Ilfov, Romania