摘要
研究了一种Ag/SiO2/Ag组成的三角形纳米柱的LSPR消光光谱特性及其传感特性.时域有限差分(FDTD)法计算结果表明,三棱柱结构在中间夹层SiO2后,消光光谱峰值出现红移现象,并伴随着折射率灵敏度的增加.随着中间介质层厚度的增加,上下两层金属间表面等离子体耦合逐渐减弱,消光光谱峰值红移速度减慢.当介质层厚度为60nm时,金属层间的表面等离子体耦合消失,消光光谱与折射率灵敏度不再发生变化.对于实际制作时可能出现尖角钝化的三棱柱结构,中间介质层仍然表现出对其光学及传感特性的良好的调节作用.
A type of Ag/SiO2 /Ag triangular nanoprism was presented and its optical properties and sensing performance were investigated. The calculation results by finite difference time domain （ FDTD） numerical method show that the peak wavelength of the extinction spectra with various dielectric thicknesses has remarkable redshift compared with single-material-composed nanoprism,and the refractive index sensitivity increases. When the thickness of SiO2 dielectric layer increases,the plasmon coupling between the top and the bottom silver layers becomes weaker and the redshift speed becomes slower. When the thickness of SiO2 reaches 60 nm,the coupling disappeared; the extinction spectra and refractive index sensitivity are immovable. For the nanoprisms with truncated vertices in experiment,SiO2 dielectric layer also shows good adjustments to its optical properties and sensing performance.
出处
《纳米技术与精密工程》
EI
CAS
CSCD
2010年第3期240-244,共5页
Nanotechnology and Precision Engineering
基金
湖南师范大学低维量子结构与调控教育部重点实验室开放课题基金资助项目(QSQC0909)
