Optical and structural characterisation of Cu doped CdS (CdS:Cu) nanoparticles J. Hasanzadeh and S. Farjami Shayesteh Eur. Phys. J. Appl. Phys., 51 3 (2010) 30601 Published online: 02 August 2010 DOI: 10.1051/epjap/2010106