摘要
为了分析Ag纳米颗粒修饰碳纳米管(AgNPs/CNTs)复合结构的表面增强拉曼散射(SERS)电磁增强特性,用FDTD Solutions软件建立了AgNPs/CNTs复合结构的仿真模型,通过改变AgNPs尺寸、颗粒之间的间距及激励光源参数对AgNPs/CNTs进行了电场强度分布的仿真计算。仿真结果表明:AgNPs/CNTs复合结构存在两种"热点",一是CNTs和AgNPs之间的耦合,二是CNTs上两个AgNPs之间的耦合。在仿真参数范围内,随着AgNPs尺寸增大,最大电场强度先增强后减弱;随着AgNPs间距增大,周围电场强度减弱;当激励光波长为532nm时,AgNPs/CNTs周围的电场强度最大。以SiO_2膜作为基底材质,当AgNPs尺寸为60nm,颗粒间距为2nm,入射光波长为532nm时,AgNPs/CNTs周围的电场强度最大,计算增强因子约为108;理论和实验都证明Ag膜基底的SERS增强效果比SiO_2膜的增强效果更好。
In order to analyze the surface-enhanced Raman scattering（SERS）electromagnetic enhancement properties of Ag nanoparticles（AgNPs）/carbon nanotubes（CNTs）composite structure,we establish the AgNPs/CNTs simulation model by FDTD Solutions software and simulate the electric field distribution of AgNPs/CNTs by changing the size of silver nanoparticles,the gap between two AgNPs,and the excitation wavelength.The simulation results show that there are two kinds of＂hot spots＂for AgNPs/CNTs composite structure,one existing between CNTs and AgNPs,and the other existing between two AgNPs on CNTs surface.It is found that,with the increase of AgNPs size,the maximum electric field intensity first increases and then decreases;with the increase of the gap between two AgNPs,the intensity of the electric field decreases;when the excitation wavelength is 532 nm,the electric field intensity around AgNPs/CNTs is the strongest.It is concluded that,taking the SiO2 film as the base material,when the size of AgNPs is 60 nm,the gap is 2 nm,and the excitation wavelength is 532 nm,the electric field intensity is the strongest and the calculated enhancement factor is about 108.The theory and experiments show that SERS enhancement effect of the Ag film is better than that of the SiO2 film.
作者
张晓蕾
张洁
朱永
Zhang Xiaolei;Zhang Jie;Zhu Yong(Key Laboratory of Optoelectronic Technology ＆ System, Ministry of Education, College of Optoelectric Engineering, Chongqing University, Chongqing 400044, Chin)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2018年第4期375-381,共7页
Acta Optica Sinica
基金
国家自然科学基金(61376121)
重庆市自然科学基金重点项目(cstc2015jcyjBX0034)
关键词
光谱学
表面增强拉曼散射
时域有限差分
碳纳米管
AG纳米颗粒
spectroscopy
surface-enhanced Raman scattering （SERS）
finite-difference time-domain
carbon nanotubes
silver nanoparticles
