Original research articleLow-temperature molten salt synthesis and characterization of Cu2ZnSnS4 ultrafine powders

Nano-crystalline particles of Cu2ZnSnS4 have been successfully synthesized by a relatively low-temperature molten salt technique. The reaction of metal chlorides with KSCN at 400 °C for 24 h led to the Cu2ZnSnS4 phase. The phase purity of Cu2ZnSnS4 nanocrystals has been confirmed by X-ray diffraction and Raman spectroscopy. The morphology and the crystallite size were evaluated by scanning and transmission electron microscopies. The Cu2ZnSnS4 nanocrystals possess an optical band gap of 1.5 eV, very close to the theoretical optimum for solar energy conversion.