Raman Spectroscopy as a Superior Tool To Understand the Synthetic Pathway of Cu2FeSnS4 Nanoparticles

The quaternary chalcogenide Cu 2 FeSnS 4 is important and interesting owing to its many advantageous characteristics for photovoltaic and optoelectronic applications, such as a suitable direct band gap (1.0–1.5 eV), low toxicity, and a relatively high abundance of the elements in the Earth's crust. To date, most of the reports on Cu 2 FeSnS 4 have focused on the synthetic method and optical properties, and few studies have comprehensively and systematically reported the growth mechanism of Cu 2 FeSnS 4 nanoparticles. Therefore, we have synthesized Cu 2 FeSnS 4 nanocrystals by a simple hot-injection method and performed detailed characterizations. Raman spectroscopy is a characterization tool to differentiate the mixed-composition phases in the synthetic pathway of Cu 2 FeSnS 4 nanocrystals, which cannot be efficiently distinguished by X-ray diffraction. A possible synthesis mechanism for Cu 2 FeSnS 4 has been proposed. Graphical Few studies have systematically reported the growth mechanism of Cu 2 FeSnS 4 nanoparticles. The XRD patterns of these quaternary compounds are difficult to interpret, as their structural similarity to the binary chalcogenides of the same elements results in overlapping diffraction peaks. We use Raman spectroscopy as a sensitive characterization technique to understand the pathway to Cu 2 FeSnS 4 .