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 center dot 2H(2)O, Zn(Ac)(2)center dot 2H(2)O and SnCl4 center dot 5H(2)O 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 C, 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.