本文用时域有限差分法研究了六角星形Ag纳米结构的消光光谱及其传感特性。计算结果表明,随着顶角角度从20°逐渐增大到140°,六角星形Ag纳米结构消光光谱峰值波长出现蓝移现象,并且强度逐渐减弱。折射率灵敏度受顶角角度影响变化很大,但角度变化对消光光谱的半高全宽的影响较小,品质因数主要受折射率灵敏度的影响在30°时最大。对于实验中顶角钝化的情况,本文分析发现,顶角钝化程度对其消光光谱也有一定影响,品质因数会随着顶角钝化的增加而减小,传感特性减弱。

The extinction spectrum and sensor properties of the single hexagram Ag nanostructure were investigated.The calculation results by finite-difference time-domain method show that the peak wavelength of the extinction spectrum of hexagram Ag nanostructure has remarkable blueshift and the intensity is gradually weakened when the vertex angle increases from 20° to 140°.Vertex angle has great influence on the refractive index sensitivity,but little effect on the FWHM of the extinction spectrum.The refractive index sensitivity but not FWHM leads to the greatest figure of merit value for LSPR applications when vertex angle is 30°.For the situation with truncated vertices in experiment,analysis of the paper shows that truncation has an effect on extinction characteristics.In addition,the figure of merit gradually decreases with the degree of angle truncation increasing.