表面活性剂PVP、CTAB协同效应对制备Cu_2ZnSnS_4微粒的影响

Influence of Surfactant PVP and CTAB Synergistic Effect on the Preparation of Cu_2ZnSnS_4 (CZTS) Particles

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,在体系中加入不同表面活性剂PVP和CTAB,研究PVP、CTAB协同效应对制备CZTS颗粒的影响。通过XRD、SEM、UV-Vis方法检测分析CZTS颗粒的物相、结构、形貌以及光学性能。结果表明:所得CZTS颗粒均具有锌黄锡矿结构;当在体系中同时加入PVP、CTAB时,两者的协同效应使得颗粒形貌发生明显变化,光学带隙也发生相应变化;当体系中加入的表面活性剂PVP∶CTAB=3∶1时,合成的颗粒结晶性较好、颗粒形貌为单分散似花状微粒、光学带隙为1.48 eV,与太阳能电池所需的最佳带隙接近。最后,提出了相应的机理。

Quaternary kesterite Cu2ZnSnS4（CZTS） particles were successfully synthesized by a facile solvothermal method in ethylene glycol with the presence of different ratio of surfactant, using CuCl2·2H2O、Zn（Ac）2·2H2O and SnCl4·5H2O as metal precursor and thiourea as sulfur source. Different morphologies CZTS particles were obtained by different contents of PVP and CTAB. The structure, morphology and absorption spectra of the as-obtained CZTS particles were characterized by means of X- ray diffraction（XRD）, scanning electron microscopy（SEM） and UV-Vis spectroscopy. The results revealed that the structure of as-synthesized CZTS particles is kesterite; the morphology and optical band-gap of CZTS has occurred a certain change with different ratios of PVP and CTAB. When PVP and CTAB ratio of 3：1 was added to the reaction system, uniform and mono-disperse flower-like CZTS particles were obtained, the band gap of the CZTS is about 1.48 eV, which approaches the optimum value for solar photoelectric conversion. Finally, a possible fabrication mechanisms of CZTS particles was also inferred.