溶剂热法制备Cu2ZnSnS4粉末及其表征

采用溶剂热法, 以CuCl₂·2H₂O、Zn(Ac)₂·2H₂O、SnCl₄·5H₂O作金属源, 硫脲作硫源, 乙二醇作溶剂, PVP作表面活性剂, 制备了Cu₂ZnSnS₄(CZTS)粉末。利用XRD、SEM、Raman、TEM、EDS、UV-Vis吸收光谱探讨了反应温度和反应时间对制备CZTS粉末的相结构、成分、形貌以及光学性能的影响。结果表明: 反应温度和反应时间对CZTS粉末的颗粒形貌和光学性能影响较大, 最佳合成温度为230℃, 反应时间24 h。该条件下生成的CZTS粉末相较为纯净、结晶完全, 形貌为表面嵌有薄片的微球, 各元素原子比接近化学计量比, 光学带隙为1.52 eV, 与太阳能电池所需的最佳带隙接近。并对其形成机理进行了初步探讨。

Synthesis and Characterization of Cu2ZnSnS4 (CZTS) Powders by Solvothermal Method

Cu₂ZnSnS₄(CZTS) powderss were synthesized by a facile solvothermal method in ethylene glycol with the presense of polyvinylpyrrolidone(PVP), using CuCl₂·2H₂O, Zn(Ac)₂·2H₂O and SnCl₄·5H₂O as metal precursor, thiourea as sulfur source. The effects of reaction temperature and time on crystal structure, composition, morphology and absorption spectra of CZTS powders were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscope, transmission electron microscope (TEM), energy dispersive X-ray spectroscope (EDS) and UV-Vis spectroscope. The results reveal that the reaction temperature and reaction time have a certain influence on the morphology and optical properties of the as-synthesized CZTS powders. The optimum solvothermal reaction condition is 230℃, 24 h. Under this condition, crystallization of the synthesized CZTS powders is pure and complete, and the particles are uniform and monodispersed sheets-contanimg microspheres. Elements’ atomic ratio of CZTS powder is close to stoichiometric coefficient and band gap of the products is about 1.52 eV, which is close to the optimum value for solar photoelectric conversion. In addition, a possible reaction mechanism of CZTS particle preparation is also inferred.