Facile Sonochemical Synthesis of Highly Luminescent ZnS−Shelled CdSe Quantum Dots

Abstract

The sonochemically driven synthesis of CdSe quantum dots (QDs) and their subsequent sonochemical ZnS shelling is described. By adapting the use of Cd(OAc)2, TOPO, and hexadecylamine to an ultrasound-driven synthesis and by applying a subsequent sonochemical ZnS shelling procedure to CdSe QD cores using Zn-ethylxanthate, highly luminescent QDs with quantum yields of 50% to 60%, narrow emission spectra (fwhm ∼25 nm), and size distributions of ∼10% were obtained. Furthermore, QD synthesis via ultrasound has several attractive features, such as a straightforward process control in the absence of any outside heat source and the ability to achieve nucleation and growth at bulk temperatures notably lower than those required for thermal techniques. The approach presented herein is accessible to laboratories with limited synthetic expertise to create CdSe/ZnS QDs.