银纳米粒子/碳纳米管阵列SERS基底增强因子分析和实验

SERS Enhancement Factor Analysis and Experiment of Carbon Nanotube Arrays Coated by Ag Nanoparticles

为了直观、准确地定量分析表面拉曼增强散射基底结构的拉曼增强,利用磁控溅射和高温退火的方法制备了银纳米粒子修饰垂直排列的碳纳米管阵列三维复合结构样品;实验采用罗丹明6G(R6G)溶剂作为探针分子,结合共聚焦显微拉曼系统,开展了表面增强拉曼增强因子(EF)分析计算的相关实验。SEM结果表明:在有序碳纳米管阵列的表面和外壁均匀地负载了大量银纳米粒子。对退火温度为450℃,退火时间为30min的样品进行了EF计算,得到其增强因子约为2.2×103,并分析了EF值低的原因主要是:在碳纳米管上溅射的银膜膜厚不均匀,导致退火后银颗粒分布不均,使得样品粗糙度值偏大,EF值较低;实验中所用的激励光源并非银纳米颗粒的优化光源。

To intuitive and accurate quantitatively analyze Raman enhancement of surface enhanced Raman scattering substrate structure,three-dimensional composite structure of silver nanoparticles modified vertically aligned carbon nanotube array is produced by magnetron sputtering and thermal annealing process;Relevant experiments using Rhodamine 6G（R6G）solution as the molecular probes are conducted to analyze surface enhanced Raman enhancement factor（EF）,combining with confocal Raman microscopy systems.The result of scanning electron microscopy（SEM）shows that a large number of silver nanoparticles are attached onto the tips and sidewalls of the ordered carbon nanotubes array uniformly.EF of the sample which was produced 30 min annealing time and 450℃ annealing temperature evaluates to 2.2×103,and the reasons for the low EF are analyzed：on the one hand,thickness of silver film sputtered on vertically aligned carbon nanotube array is non-uniform,leading to distribution of silver nanoparticles is uneven after annealing,so that the value of sample roughness is too large,EF value is low;on the other hand,the excitation light source is not the advantage wavelength of silver nanoparticles in the experiments.