Effect of ZnS shell on optical properties of Ni-doped ZnSe nanocrystals

The present paper aims to suggest a simple/fast route for direct preparation of the Ni-doped ZnSe/ZnS core/shell NCs in aqueous solution. Using XRD measurement, the zinc blend structure and sub-5 nm average size of the NCs was proved. The FT-IR spectrum also showed the passivation of the NCs surface by means of the deprotonated thiol terminals of the NAC molecules. The intensity of the dopant-related emission at about 476 nm in Ni:ZnSe doped NCs was found to experience more than four times enhancement by utilization of the extra ZnS shell. It was also observed that the increasing of the shell overcoating time from 1 to 3 h, has effective role on better passivation of the surface of the NCs and increasing of the emission intensity