1. University of Sfax, Faculty of Sciences, Laboratory of Spectroscopic Characterization and Optical Materials, 3018 Sfax, BP1171, Tunisia
2. Physico-Chemistry of Solid State Laboratory, Department of Chemistry, Faculty of Sciences of Sfax, 3000 Sfax, BP1171, Tunisia
3. University of Sfax, Faculty of Sciences of Sfax, Department of Physic, Laboratory of Applied Physic, B.P. No. 802, 3018 Sfax, Tunisia
4. Institute for Molecules and Materials Le Mans, University of Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France