论文部分内容阅读
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.
The LSPR extinction spectra and sensing characteristics of a Ag / SiO2 / Ag triangular array were investigated.The FDTD results show that the peak of extinction spectrum appears after the interlayer of SiO2 in the triangular prism structure Redshift phenomenon accompanied by the increase of the refractive index sensitivity.With the increase of the thickness of the intermediate layer, the plasma coupling between the upper and lower layers gradually weakened and the peak redshift velocity of the extinction spectrum slowed down.When the thickness of the medium layer was 60 nm , The surface plasmon coupling between the metal layers disappears and the extinction spectrum and the refractive index sensitivity no longer change. For the practical production, there may be sharp-pointed passivated triangular prism structures, and the intermediate dielectric layer still exhibits optical and sensing characteristics Good regulatory role.