Synthesis of highly luminescent ZnS QDs in aqueous solution

The synthesis of quantum dots (QDs) of direct band gap semiconductor cubic ZnS through modified green chemistry-mediated chemical precipitation reaction is presented. Green chemistry-synthesized ZnS QDs were characterized using X-ray diffraction and dynamic light scattering. UV-Vis absorption spectroscopy (Eg = 3.83.4.3 eV) showed a distinct blue shift than the bulk. An intense and broad photoluminescence band with a maximum at 430 nm was found for samples with high pH of the solution. Zeta potential (up to minus 80 mV) evidently proved the existence of stable ZnS QDs in the water solution.