Solvothermal synthesis of highly crystallized quaternary chalcogenide Cu2FeSnS4 particles

• Cu2FeSnS4 particles were successfully synthesized by a solvothermal method.
• The Cu2FeSnS4 particles had high crystallinity and large grain size of over 100 nm.
• The Cu2FeSnS4 particles exhibited strong absorption in the whole visible range.

Quaternary chalcogenide Cu2FeSnS4 (CFTS) particles, a potential candidate for application as absorber layer in thin film solar cells, were successfully synthesized by using a convenient solvothermal method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results revealed that the CFTS particles possessed pure tetragonal structure with high crystallinity. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) results showed that the average size of the CFTS particles was about 200 nm and the composition of products was close to the stoichiometry of CFTS. UV–vis absorption spectrum showed that the CFTS particles had a broad absorption band in the whole visible range with a band gap of 1.28 eV, which are promising for photovoltaic applications.