纳米结构Si表面增强拉曼散射特性研究

为了实现低成本高灵敏度的表面增强拉曼散射效应，制备了一种基于硅表面纳米结构的表面增强拉曼散射效应（SERS）衬底。首先利用低能反应离子注入的方法对单晶硅进行表面处理，制作高陡值度的墙壁结构。然后采用电子束蒸发的方式在硅片表面蒸镀银膜，高密度的银纳米点阵列出现在侧壁表面，形成大量的热点。实验采用罗丹明6G（R6G）作为探针分子进行表征，发现获得最强拉曼信号的银膜厚度为40 nm，R6G的探测极限能达到10^-14 mol/L；同时分析衬底的重复性和稳定性，发现在614 cm^-1和1 650 cm^-1处的拉曼信号特征峰的相对标准偏差分别达到12.3%和14.3%，保存一个月的衬底测得的拉曼信号强度保持不变。本研究提供了一种操作简单、成本低的制备高灵敏度增强拉曼效应衬底的方法，制备的衬底具有高信号可重复性和高稳定性的优点。

Surface-enhanced Raman Scattering Based on Silicon Nanostructures

In order to achieve high-sensitivity surface-enhanced Raman scattering(SERS) at a low cost, a kind of SERS substrate based on the nanostructures of silicon was fabricated. The monocrystalline silicon was treated with low-energy reactive ion implantation. Highly steep nanostructures were fabricated on the surface of the monocrystalline silicon. Then the treated silicon was decorated with silver employing the way of electron beam evaporation. Ag nanoparticles and ‘hot spots’ formed on the side walls of nanostructures. The substrates with 40 nm-thickness silver obtain the most powerful Raman signal and reach a limit of 10^-14 mol/L by employing the R6G as the probe molecule. We also analyze the stability and repeatability of the substrates. The characteristic peaks located at 614 cm^-1 and 1 650 cm^-1 own relative standard deviation of 12.3% and 14.3%, respectively. The substrates can obtain the characteristic signal of R6G as well after a month. This method is simple and cost-effective and the demonstrated SERS substrates offer the advantages of high-sensitivity, high-repeatability and high-stability.