In this work, we report the fabrication of copper sulfide (CuS, Cu_1.39S, and Cu₂S) thin films with tunable localized surface plasmon resonance (LSPR). The thin films were synthesized by keeping the Cu precursor concentration constant and varying that of sodium thiosulfate, which dictated the final Cu_xS product. CuS showed the highest intensity LSPR peak and its intensity decreased with the increasing incorporation of Cu, as in the case of Cu_1.39S, and vanished for the Cu‐rich Cu₂S, indicating carrier concentration‐dependent plasmonic absorption. The shift in the XRD peak positions towards a lower degree and the increase in the d‐spacing values for CuS indicated the intercalation of Cu species in the initial covellite lattice, yielding Cu_1.39S and Cu₂S in the process. XPS valence band edge studies revealed that among the synthesized Cu_xS thin films, CuS showed a stronger p‐type as compared to Cu_1.39S and Cu₂S.

中文翻译：

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具有可调局部表面等离子体共振的CuxS薄膜的合成

在这项工作中，我们报告了具有可调局部表面等离子体激元共振（LSPR）的硫化铜（CuS，Cu _1.39 S和Cu ₂ S）薄膜的制造。通过保持铜前驱体浓度恒定并改变硫代硫酸钠的浓度来合成薄膜，这决定了最终的Cu _x S产物。CuS表现出最高强度的LSPR峰，并且其强度随Cu掺入量的增加而降低，例如Cu _1.39 S的情况，而对于富含Cu的Cu _2则消失了S，表示取决于载流子浓度的等离子体吸收。朝向较低的程度和对硫化铜的d间距值的增加，XRD峰位置的移位所指示的Cu物种的嵌入在初始铜蓝晶格，得到的Cu _1.39 S和铜₂中的S的过程。XPS价带边缘研究表明，在合成的Cu _x S薄膜中，与Cu _1.39 S和Cu ₂ S相比，CuS显示出更强的p型。