The study of optical properties of ZnS, ZnS:Co2+ nanoparticles C. Vatankhah, M. H. Yuosefi, A. A. Khosravi and M. Savarian Eur. Phys. J. Appl. Phys., 48 2 (2009) 20601 Published online: 02 October 2009 DOI: 10.1051/epjap/2009157