Facile synthesis of phase-pure FeCr2Se4 and FeCr2S4 nanocrystals via a wet chemistry method

Abstract

We report a novel facile route for synthesis of iron-based ternary nanocrystals (NCs), i.e., FeCr₂Se₄ and FeCr₂S₄, using a wet chemistry method. The electronic structure with a narrow band gap of Fe-based ternary semiconducting NCs with different dopants offers promising conductive properties. Owing significantly to the non-toxicity of their constituent materials, they exhibit higher potential for being utilized in solar cells than Cd and Pb-based compounds. The general route for synthesis of ternary compounds includes mixing and reacting of different elemental powders in evacuated silica ampoules for long periods of time under high temperature (700–1000 °C). However, this process results in an uncontrolled size and morphology of the colloidal NCs. In our proposed method, the NC morphology was easily controlled by the solvent and heating temperature, utilizing oleylamine as a surfactant, solvent, and reducing agent. The synthesized NCs possess excellent mono-dispersity of size and shape without any aggregation and the conductivities of the deposited layer of FeCr₂Se₄ and FeCr₂S₄ NCs are 3.25 μA and 2.33 μA, respectively. Therefore, these iron-based NCs may replace the use of chalcogenides that are known to be environmentally toxic, and may contribute to low efficiency of energy transfer.