Fabrication and Characterization of Cu_2ZnSnS_4(CZTS) Microparticles

Quaternary kesterite Cu2ZnSnS4(CZTS) micro-particles were successfully synthesized by a facile solvothermal method in ethylene glycol with the presence of Polyvinylpyrrolidone(PVP) as surfactant,using CuCl2·2H2O、Zn(Ac)2·2H2O and SnCl4.5H2O as metal precursor and thiourea as sulfur source.Different dispersion CZTS particles were obtained by different contents of PVP.The structure,morphology and absorption spectra of the as-obtained CZTS particles were characterized by means of X-ray diffraction(XRD),Raman spectroscopy,scanning electron microscopy(SEM),transmission electron microscopy(TEM),UV-Vis spectroscopy.The results revealed that the structure of as-synthesized CZTS microparticles is kesterite;the morphology of CZTS has occurred a certain change with different contents of PVP.When 0.2g of PVP was added to the reaction system,uniform and monodisperse CZTS MCs containing nanosheets were obtained.The nanosheets was more compact than the reaction system with 0.1 g of PVP.The band gap of the CZTS is about 1.47 eV,which approaches the optimum value for solar photoelectric conversion.Finally,a possible fabrication mechanisms of uniform and monodisperse CZTS MCs containing nanosheets was also inferred.