1. Higher School of Sciences and Technology of Hammam Sousse, University of Sousse, 4011 Sousse, Tunisia
2. MINOS, Universitat Rovira i Virgili, Avinguda Països Catalans, 26, 43007 Tarragona, Spain
3. NANOMISENE Laboratory, LR16CRMN01, Center of Research on Microelectronics and Nanotechnology (CRMN), Technopole of Sousse, B.P334, 4054 Sousse, Tunisia
4. Fakultät V – Institute of Physics, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg, Germany