Au纳米粒子二维周期阵列的LSPR消光特性分析

采用离散偶极子近似(DDA)方法,对不同间距的Au纳米粒子阵列在不同介质情况下的消光特性进行仿真分析。分析结果表明,消光峰值波长和强度随纳米粒子间距的减小而增大,但在间距较大的情况下折射率灵敏度基本不变。实验测量结果也表明,不同的密度分布的Au纳米球阵列对应了基本相同的折射率灵敏度。因此,在纳米粒子间距较大时,纳米粒子阵列局部分布的不均匀不会改变整体的折射率灵敏度,相同的消光峰值波长红移量对应相同的介质折射率变化量。

Analysis of LSPR extinction properties of two-dimensional Au nanoparticle arrays

The extinction properties of the Au nanoparticle arrays with different spacings in different media are simulated by Discrete Dipole Approximation(DDA) method.The simulation result demonstrates that the extinction wavelength and intensity increase with the decreasing spacing,but the refractive index(RI) sensitivity remains constant while the spacing is large enough.And the experimental measurements of the Au nanosphere arrays assembled on the glass substrate also obtain the same RI sensitivity with different density distributions of nanoparticles in the arrays.Therefore,the local uneven distribution of the nanoparticle arrays would not change the RI sensitivity as the spacing between nanoparticles is large enough,and the red-shift of the extinction wavelength and the RI change of the surrounding medium are related directly.