Facile phosphine-free synthesis of CdSe/ZnS core/shell nanocrystals without precursor injection

Abstract

A new simple method for synthesis of core/shell CdSe/ZnS nanocrystals (NCs) is present. By adapting the use of cadmium stearate, oleylamine, and paraffin liquid to a non-injection synthesis and by applying a subsequent ZnS shelling procedure to CdSe NCs cores using Zinc acetate dihydrate and sulfur powder, luminescent CdSe/ZnS NCs with quantum yields of up to 36% (FWHM 42-43 nm) were obtained. A seeding-growth technique was first applied to the controlled synthesis of ZnS shell. This method has several attractive features, such as the usage of low-cost, green, and environmentally friendlier reagents and elimination of the need for air-sensitive, toxic, and expensive phosphines solvent. Furthermore, due to one-pot synthetic route for CdSe/ZnS NCs, the approach presented herein is accessible to a mass production of these NCs.