Mechanochemical Solvent-Free Synthesis of Quaternary Semiconductor Cu-Fe-Sn-S Nanocrystals

Abstract

In this study, we demonstrate a one-pot mechanochemical synthesis of the nanocomposite composed of stannite Cu2FeSnS4 and rhodostannite Cu2FeSn3S8 nanocrystals using a planetary ball mill and elemental precursors (Cu, Fe, Sn, S). By this approach, unique nanostructures with interesting properties can be obtained. Methods of XRD, Raman spectroscopy, UV-Vis, nitrogen adsorption, SEM, EDX, HRTEM, STEM, and SQUID magnetometry were applied. Quaternary tetragonal phases of stannite and rhodostannite with crystallite sizes 18–19 nm were obtained. The dominant Raman peaks corresponding to the tetragonal stannite structure corresponding to A-symmetry optical modes were identified in the spectra. The bandgap 1.25 eV calculated from UV-Vis absorption spectrum is very well-acceptable value for the application of the synthesized material. The SEM micrographs illustrate the clusters of particles in micron and submicron range. The formation of agglomerates is also illustrated on the TEM micrographs. Weak ferromagnetic properties of the synthesized nanocrystals were documented.

Chalcogenide Quaternary Cu2FeSnS4 Nanocrystals for Solar Cells: Explosive Character of Mechanochemical Synthesis and Environmental Challenge

“…Regarding stannite, we obtained a slightly higher value compared to that presented in our previous paper (3.5 m 2 ·g −1 ) [30], in which the sample was prepared in P6 mill with slightly higher ball-to-powder ratio, which could lead to more intensive agglomeration. Also the different conditions of milling could influence the value.…”

“…The XRD pattern exhibits a complex of peaks with the three most intensive ones corresponding to (112), (204) and (312) planes of the tetragonal nanocrystals. More complex elucidation of the XRD data has been performed in our previous paper [30]. …”

“…The optical band gap energy of the CFTS sample was determined by plotting (αhν) 2 as a function of the photon energy (hν) and extrapolating the linear portion of the spectrum in the band edge region, as it is displayed in the inset of Figure 5. The band gap energy was calculated by a procedure described in paper [30]. The obtained value 1.27 eV is acceptable for absorbers in solar cells [34,35].…”

“…However, milling has been applied only for homogenization of reaction mixture and the synthesis process was carried out subsequently at 400 • C for eight hours in argon atmosphere. The only two papers reporting CFTS mechanochemical synthesis are by the authors of this work [30,31]. The authors studied the kinetics of mechanochemical synthesis and magnetic properties of the prepared nanocrystals.…”

Temperature Dependence of Raman Spectra in Cu2FeSnS4 Magnetic Semiconductor Compound

“…Cu 2 FeSnS 4 (CFTS), which belongs to the family of Cu 2 B II C IV magnetic semiconducting compounds, where B is a paramagnetic atom (B = Fe, Mn or Co; C = Si, Ge or Sn; and X = S, Se or Te), in the form of bulk crystals, thin films and nanoparticles has received some attention recently . This is mainly because in these compounds, unlike to that observed in the B II X VI binary dilute magnetic semiconductors, two nearest neighbor B II paramagnetic ions never bind to a common S VI anion.…”