Discovery and evaluation of a single source selenium sulfide precursor for the synthesis of alloy PbSxSe1-x nanocrystals

In this article, we evaluate the use of a novel single source SemSn precursor for the synthesis of alloy PbSxSe1-x nanocrystals using oleylamine as stabilizing ligand, reagent and solvent. The precursor is prepared by quenching a stoichiometric melt of S and Se. We found that this precursor, like the related sulfur-oleylamine solution popular for the synthesis of metal sulfide nanocrystals, is tolerant of air and moisture and allowed for the simple and fast preparation of nanocrystals at relatively low reaction temperatures. The resulting nanocrystals were shown to form a homogeneous alloy using electron microscopy, elemental mapping, and powder X-ray diffraction with Vegard analysis. The precursor reactivity was studied with Se-77 NMR and Raman spectroscopy and was shown to form H2Se and H2S in situ in an analogous fashion to sulfur-oleylamine, which liberates H2S.