In this paper, we study the DMSO/thiourea/chloride salt system for synthesis of pure-sulfide \(\hbox {Cu}_2\hbox {ZnSnS}_{4}\) (CZTS) thin-film solar cells under ambient conditions. We map out the ink constituents and determine the effect of mixing time and filtering. The thermal behavior of the ink is analyzed, and we find that more than 90% of the solvent has evaporated at \(250\,^{\circ }\hbox {C}\). However, chloride and sulfoxide species are released continually until \(500\,^{\circ }\hbox {C}\), suggesting the advantage of a higher pre-annealing temperature, which is also commonly observed in the spin-coating routines in literature. Another advantage of a higher pre-annealing temperature is that the worm-like pattern in the spin-coated film can be avoided. We hypothesize that this pattern forms as a result of hydrodynamics within the film as it dries, and it causes micro-inhomogeneities in film morphology. Devices were completed in order to finally evaluate the effect of varying thermal exposure during pre-annealing. Contrary to the previous observations, a lower pre-annealing temperature of \(250\,^{\circ }\hbox {C}\) results in the best device efficiency of 4.65%, which to the best of our knowledge is the highest efficiency obtained for a pure-sulfide kesterite made with DMSO. Lower thermal exposure during pre-annealing results in larger grains and a thicker \(\hbox {MoS}_2\) layer at the CZTS/Mo interface. Devices completed at higher pre-annealing temperatures display the existence of either a Cu-S secondary phase or an incomplete sulfurization with smaller grains and a fine-grain layer at the back interface.

在本文中，我们研究了在环境条件下用于合成纯硫化物\（\ hbox {Cu} _2 \ hbox {ZnSnS} _ {4} \）（CZTS）薄膜太阳能电池的DMSO /硫脲/氯化物盐体系。我们绘制出墨水成分并确定混合时间和过滤的效果。分析了墨水的热行为，我们发现90％以上的溶剂已在\（250 \，^ {\ circ} \ hbox {C} \）处蒸发。但是，氯化物和亚砜物质会持续释放，直到\（500 \，^ {\ circ} \ hbox {C} \），表明了较高的预退火温度的优势，这在文献中的旋涂程序中也很常见。较高的预退火温度的另一个优点是可以避免旋涂膜中的蠕虫状图案。我们假设这种图案是由于薄膜干燥过程中的流体动力学而形成的，并且会引起薄膜形态的微观不均匀性。为了最终评估在预退火期间变化的热暴露的影响，完成了设备的制作。与以前的观察相反，较低的预退火温度为\（250 \，^ {\ circ} \ hbox {C} \）产生的最佳器件效率为4.65％，据我们所知，这是用DMSO制得的纯硫化钾酯的最高效率。预退火过程中较低的热暴露导致CZTS / Mo界面处的晶粒更大，并且\（\ hbox {MoS} _2 \）层更厚。在较高的预退火温度下完成的器件显示出存在Cu-S第二相，或者存在不完整的硫化，具有较小的晶粒和背面处的细晶粒层。