We take hexagonal boron nitride (hBN) flakes exfoliated on SiO /Si substrates as a prototype, to demonstrate how to enhance the Raman signals both from ultra-thin layered materials and the underlying opaque substrate excited by deep ultraviolet (DUV) laser. We found that the interference effect in the hBN/SiO /Si multilayered structure can largely enhance Raman intensity of hBN flake and the underlying Si substrate under 266-nm excitation. This enhancement effect is more significant than that under visible excitation. With increasing the thickness of SiO layer in the substrate, the corresponding hBN and Si Raman intensity can vary by up to ∼ 4 and ∼2 orders of magnitude under 266-nm excitation, respectively. This method can be applicable to enhance Raman signal from other two-dimensional materials under DUV excitation by tuning the thickness of SiO layer in the SiO /Si substrate.

中文翻译：

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六方氮化硼薄片及其下层硅衬底的干涉增强深紫外拉曼信号

我们以在 SiO /Si 衬底上剥离的六方氮化硼 (hBN) 薄片 作为原型，展示了如何增强来自超薄层状材料和深紫外 (DUV) 激光激发的底层不透明衬底的拉曼信号。我们发现 hBN/SiO /Si 多层结构中的干涉效应 可以在 266 nm 激发下大大增强 hBN 薄片和下面的 Si 衬底的拉曼强度。这种增强效果比在可见光激发下更显着。随着 SiO2 厚度的增加 在衬底中的层，相应的 hBN 和 Si 拉曼强度在 266 nm 激发下可以分别变化高达 ~ 4 和 ~ 2 个数量级。该方法可用于通过调整SiO /Si 衬底中 SiO层 的厚度来增强 DUV 激发下来自其他二维材料的拉曼信号 。