Mercury-indium-sulfide nanocrystals: A new member of the family of ternary in based chalcogenides

A general synthesis approach of aqueous glutathione-capped ternary Ag–In–S, Cu–In–S, and Hg–In–S nanocrystals (NCs) is introduced, allowing the NC composition to be varied in a broad range. Ternary Hg–In–S (HIS) NCs are reported for the first time and found to have the same tetragonal chalcopyrite motif as Cu–In–S and Ag–In–S NCs, corroborated by phonon spectra, while X-ray photoelectron spectroscopic data indicate mercury to be present as Hg+ in the Hg–In–S NCs. Colloidal HIS and Hg–In–S/ZnS NCs showed little or no variations of the spectral width of the photoluminescence band upon NC size selection, temperature variation in a broad range of 10–350 K, deposition of a ZnS shell, or postsynthesis annealing. All these observations are similar to those reported earlier for Ag–In–S and Ag–In–S/ZnS NCs and allowed us to assume a general photoluminescence mechanism for all three ternary compounds, based on the model of radiative self-trapped exciton recombination.