Liang Xiaojuan

L-cystine-Assisted Growth and Mechanism of CuInS2 Nanocrystallines via Solvothermal Process

L-cystine is successfully used as a kind of sulfur source to grow CuInS2 nanocrystallines at 200° C for 18 h in a mixed solution made of 20 mL ethylenediamine and 20 mL distilled water. The diameter of the CuInS2 nanocrystallines ranges from 300 to 500 nm. The structure of nanocrystallines is determined to be of the tetragonal phase of CuInS2. A reasonable possible mechanism for the growth of CuInS2 nanocrystallines is proposed. The as-obtained CuInS2 products are examined using diverse techniques including x-ray powder diffraction, x-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction and high-resolution transmission electron microscopy.

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.