Zhong Jiasong

溶剂热法制备球状Cu 2 ZnSnS 4 纳米晶及其表征

A simple solvothermal route has been successfully used to prepare Cu2ZnSnS4 nanocrystals using metal chloride and L-cysteine as precursors at 180 °C for 16 h. L-cysteine was used as the sulfide source and complexing agent. The phase, structure, morphology, and optical properties of the as- synthesized products were characterized by powder X-ray diffraction (XRD), field-emission scan electron microscopy (FESEM), energy dispersive spectrometry (EDS), high-resolution electron transmission microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible (UV-Vis) spectrophotometer. The results showed that pure kesterite-type Cu2ZnSnS4 nanocrystals were prepared under this condition and the diameters of the microspheres were about 400-800 nm while the microspheres consisted of nanoflakes with thickness of 20 nm. The band gap of CZTS nanoparticles was about 1.58 eV,which was close to the optimum band gap of thin film solar cells. A possible formation mechanism was also discussed.