Ultrathin two-dimensional transition metal dichalcogenides represent a promising new class of materials with surface-enhanced Raman scattering (SERS) activities. Previous work mainly focused on the SERS effects of transition metal dichalcogenide crystals with sizes of micrometer scale. The enhancement effect is usually nonuniform on the SERS substrates. In this paper, we report a chemical vapor deposition method for the preparation of centimeter-scale MoSe₂ films with uniform and high SERS activity. The molybdenum precursors are supplied in a “face-to-face” manner from a silica gel plate to the growth substrate, which guarantees uniform nucleation and growth of the monolayer MoSe₂. We demonstrate that the monolayer MoSe₂ film has strong SERS effect, which can be attributed to charge transfer between MoSe₂ and the probe molecules. The detection limit of Rhodamine B on monolayer MoSe₂ is determined to be 10−7mol/L, and the Raman enhancement factor is estimated to be 5.58×104. Due to its atomic uniformity and chemical stability, the MoSe₂ film can serve as an ideal two-dimensional SERS material for detection of various molecules.

中文翻译：

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用于表面增强拉曼散射分析的大面积 MoSe2 单层薄膜的合成

超薄二维过渡金属二硫化物代表了一类具有表面增强拉曼散射（SERS）活性的有前途的新型材料。以前的工作主要集中在微米级尺寸的过渡金属二硫属化物晶体的SERS效应。SERS 基板上的增强效果通常是不均匀的。在本文中，我们报道了一种化学气相沉积方法，用于制备具有均匀和高 SERS 活性的厘米级 MoSe _2薄膜。钼前驱体以“面对面”方式从硅胶板供应到生长基板，保证了单层 MoSe ₂的均匀成核和生长。我们证明了单层 MoSe ₂薄膜具有很强的SERS效应，这可以归因于MoSe ₂和探针分子之间的电荷转移。罗丹明B对单层MoSe ₂的检测限确定为10-7mol/L，拉曼增强因子估计为5.58×104. 由于其原子均匀性和化学稳定性，MoSe ₂薄膜可以作为理想的二维SERS材料用于检测各种分子。