红外与激光工程, 2017, 46 (2): 0216001, 网络出版: 2017-03-31  

米状银纳米颗粒对局域电场增强的理论模拟

Theoretical simulation of enhancement of local electric field by rice-shaped silver nanoparticles
作者单位
1 燕山大学 理学院, 河北 秦皇岛 066004
2 燕山大学 里仁学院, 河北 秦皇岛 066004
摘要
为了提高表面增强拉曼散射技术中基底的增强效果, 采用时域有限差分算法从理论上对不同入射光偏振方向下米状银纳米颗粒的电场增强进行了模拟分析, 分别研究了单个银纳米颗粒和不同组合的二聚体以及三聚体的形状、间距对局域电场强度的影响, 并且详细讨论了导致电场增强的原因。结果表明, 当米状银纳米颗粒长度约为300 nm时, 应控制其短轴约为36 nm, 间距约为2 nm, 且入射光偏振方向平行于长轴, 此时在颗粒的尖端处均会产生最大电场增强, 其中二聚体尖端对尖端情形下增强效果尤为明显。该结论为拉曼基底实验中纳米颗粒的制备提供了一定的理论基础。
Abstract
Raman scattering and surface-enhanced Raman scattering (SERS) have attracted the attention of researchers due to the great potential applications in various research fields, including biomolecular sensing, analytical chemistry, surface science and material science. In order to improve the enhancement effect of the SERS substrate, the electric field enhancement of rice-shaped silver monomer, dimer, and trimer nanoparticles was simulated by the finite difference time domain method under different polarzation directions. The influence of the shape and spacing of the nanoparticles on local elecric field intensity were also studied and analyzed. On the above basis, the causes of electirc field enhancement were discussed in detail. The result shows that the electric field distributions of rice-shaped silver nanoparticles are different by changing the shape and spacing of the nanoparticles, as well as the polarization direction. The tip of the rice-shaped silver nanoparticle with long axis 300 nm, minor axis 36 nm and spacing 2 nm can produce maximum electric field enhancement when the incident polarization direction is parallel to the long axis. Moreover, due to the strong coupling between the nanoparticles, there is an obvious enhancement effect in the case of top to top configuration, and the obtained SERS enhancement factor (EF) is up to 2.4×1011. The conclusion provides theoretical basis for the preparation of silver nanoparticles in the SERS experiments.

王明利, 朱艳英, 魏勇, 张乐. 米状银纳米颗粒对局域电场增强的理论模拟[J]. 红外与激光工程, 2017, 46(2): 0216001. Wang Mingli, Zhu Yanying, Wei Yong, Zhang Le. Theoretical simulation of enhancement of local electric field by rice-shaped silver nanoparticles[J]. Infrared and Laser Engineering, 2017, 46(2): 0216001.

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!