Control of Metal‐Ion Composition in the Synthesis of Ternary II‐II′‐VI Nanoparticles by Using a Mixed‐Metal Cluster Precursor Approach

Abstract

The ternary molecular nanoclusters [Zn_xCd_10−xSe₄(SePh)₁₂(PnPr₃)₄] (x=1.8, 1 a; x=2.6, 1 b) were employed as single‐source precursors for the synthesis of high‐quality hexagonal Zn_xCd_1−xSe nanocrystals. The tellurium clusters [Zn_xCd_10−xTe₄(TePh)₁₂(PnPr₃)₄] (x=1.8, 2 a; x=2.6, 2 b) are equally convenient precursors for the synthesis cubic Zn_xCd_1−xE nanoparticles. The thermolysis of the cluster molecules in hexadecylamine provides an efficient system in which the inherent metal‐ion stoichiometry of the clusters is retained in the nanocrystalline products, whilst also affording control of particle size within the 2–5 nm range. In all cases, the nanoparticles are monodisperse, and luminescence spectra exhibit emission energies close to the absorption edge. Analysis of the optical spectra and X‐ray diffraction patterns of these materials indicates a metal‐ion concentration gradient within the structures of the nanocrystals, with Zn^II ions predominantly located near the surface of the particles.