Synthesis of high quality and monodisperse CdS:Mn2+/ZnS and CdS:Mn2+/CdS core–shell nanoparticles

CdS:Mn2+/ZnS and CdS:Mn2+/CdS core–shell nanoparticles were synthesized in aqueous medium via chemical precipitation method in an ambient atmosphere. Polyvinylpyrrolidone (PVP) was used as a capping agent. The effect of the shell (ZnS and CdS) thickness on CdS:Mn2+ nanoparticles was investigated. Inorganically passivated core/shell nanocrystals having a core (CdS:Mn2+) diameter of 4 nm and a ZnS-shell thickness of ∼0.5 nm exhibited improved PL intensity. Optimum concentration of doping ions (Mn2+) was selected through optical study. For all the core–shell samples two emission peaks were observed, the first one is band edge emission in the lower wavelength side due to energy transfer to the Mn2+ ions in the crystal lattice; the second emission is characteristic peak of Mn2+ ions (4T1 → 6A1). The XRD, TEM and PL results showed that the synthesized core–shell particles were of high quality and monodisperse.

► CdS:Mn/ZnS and CdS:Mn/CdS core–shell nanoparticles were synthesized through chemical method in an air atmosphere. ► The effect of organic capping agent on an inorganically passivated CdS:Mn core–shell nanoparticles was investigated. ► An optimum level of doping ions, capping agent and shell thickness was found by optical study.