A simple chemical route has been deployed to
synthesis highly monodispersed and controllable ZnS and CdS
nanoparticles (quantum dots) doped with Mn. XRD investigations shows the
cubic structure of both ZnS and CdS nanoparticles and doping has no effect
on the structure. The size measurement gives an approximate size of
1.5 nm and 2.5 nm for ZnS:Mn and CdS:Mn quantum dots respectively by
Deby-Shreer. UV-Visible is used to study the Optical absorption of ZnS and
CdS pure as well as doped nanoparticles. Furthermore as the
chemical parameters change, the size of quantum dots change systemically.
Of course although doping percentage is a significant
parameter in photoluminescence properties of quantum dots, but it
has no effect on the size. Photoluminescence spectra obtained at 6% molar
of the Mn dopant in CdS:Mn (Ex = 315, Em = 495 nm) and ZnS:Mn (Ex = 285,
Em = 572 nm). Microscopic images (SEM, TEM) show the 1–3 nm size for ZnS
and CdS nanoparticles.