Preparation of Cu2FeSnS4 Single Crystals by Molten Salt Method

Micron-sized Cu2FeSnS4 single crystals were synthesized by molten salt method using CuS, FeS and SnS as raw materials and using CsCl as fluxing agent for the first time. The Cu2FeSnS4 single crystals were investigated by X-ray diffraction, Raman, X-ray photoelectron spectroscopy and UV-vis absorbance spectroscopy. The results showed that the Cu2FeSnS4 single crystals were having stannite structure with an average size about 50–100 μm and the band gap was about 1.45 eV.