Influence of solution temperature on the properties of Cu2ZnSnS4 nanoparticles by ultrasound-assisted microwave irradiation

In this paper, Cu2ZnSnS4 (CZTS) nanoparticles were synthesized by applying ultrasound and microwave irradiation simultaneously. The effects of solution temperature on properties of CZTS nanoparticles were studied by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), and UV–vis spectroscopy. The results showed that as-synthesized CZTS nanoparticles had a single phase and stoichiometric composition, when solution temperature was kept at 180 °C. However, when solution temperature was low, the as-prepared nanoparticles contained Cu2−xS, Cu2SnS3 and ZnS secondary phases according to the results of XRD and Raman spectroscopy. Furthermore, TEM showed that the rod-like and hexagonal plate-like nanoparticles formed at low solution temperature. The crystallinity of as-prepared nanoparticles increased with the increasing solution temperature. Moreover, the band gap of CZTS nanoparticles obtained at 180 °C was 1.58 eV, and that obtained at low temperature was large due to secondary phases.