This report demonstrates nontoxic colloidal nitrate route CZTS (Cu₂ZnSnS₄) synthesis at room temperature, along with their band grading due to incorporation of Ge as cost of Sn (3%). The parent CZTS, CZGTS (Cu₂ZnGeSnS₄), and their polyvinyl alcohol (PVA), dimethyl sulfoxide (DMSO) solvent containing solutions doctor blade-coated thin film structural and optical properties are discussed. Their sulfurized thin films thickness have been achieved ±2 μ. It has noticed that addition of Ge in CZTS alloy affects the grain sizes, crystallographic structure, Raman spectral peak shift toward the higher wave number side. The addition of PVA and DMSO is also substantially contributed in their physical property modification by demonstrating the gradual improvement in grain sizes and compactness. Moreover, the gradual changes have also appeared in their X-ray diffractometer (XRD) and Raman spectroscopic results. The optical energy band gaps of the CZTS, CZGTS, and their PVA, DMSO mixed alloyed thin films are obtained in between 1.27 eV to 1.57 eV and 1.58 eV to 1.83 eV.

中文翻译：

---

溶剂和掺Ge对CZTS薄膜结构和光学性能的影响

该报告证明了室温下无毒的硝酸胶体路线CZTS（Cu ₂ ZnSnS ₄）的合成，以及由于掺入Ge作为Sn的成本（3％）而导致的谱带分级。讨论了母体CZTS，CZGTS（Cu ₂ ZnGeSnS ₄）及其聚乙烯醇（PVA），二甲基亚砜（DMSO）溶剂溶液的刮涂式薄膜结构和光学性能。其硫化薄膜厚度已达到±  2μ。已经注意到，在CZTS合金中添加Ge会影响晶粒尺寸，晶体结构，拉曼光谱峰向较高波数侧偏移。通过证明晶粒尺寸和致密性的逐渐提高，PVA和DMSO的添加也极大地有助于其物理性质的改变。此外，它们的X射线衍射仪（XRD）和拉曼光谱结果也出现了逐渐变化。CZTS，CZGTS及其PVA，DMSO混合合金薄膜的光能带隙在1.27 eV至1.57 eV和1.58 eV至1.83 eV之间。