Lanthanide-doped CdS quantum dots: luminescence and paramagnetic properties

Optical and magnetic properties of CdS quantum dots (QDs) doped with europium(II) and gadolinium(III) ions were studied. l -Cysteine stabilized nanoparticles were synthesized by the colloidal method in aqueous media. The QDs obtained have a hexagonal crystal lattice. The nanoparticle size varies from 3 to 14 nm. The EPR spectra of nanoparticles prepared in different conditions were measured and analyzed. Dependences of the optical properties of nanoparticles on the reaction time and pH values were studied. The dependence of the luminescence properties of CdS QDs on the dopant ion type was established. It was shown that the increase in the reaction time and medium pH values favors a bathochromic shift of maxima in the luminescence spectra of nanoparticles.