论文部分内容阅读
利用离散偶极近似(Discrete Dipole Approximation-DDA)算法,从理论上模拟分析了金银核壳结构复合纳米颗粒的消光光谱以及不同核壳厚度、不同介质折射率情况下峰位的变化情况。研究结果表明,随着壳层厚度的增加,复合纳米颗粒的消光谱线先逐渐形成两个与单质金属纳米颗粒相似的消光峰,后又逐渐合为一个半峰宽度较宽的消光峰;在不同介质环境中复合纳米颗粒的消光峰都随着介电常数的增大出现红移;无论是作为核层还是壳层,银对总体消光谱线的作用都要比金强。
Discrete Dipole Approximation (DDA) algorithm was used to theoretically simulate the extinction spectra of Au-Ag core-shell composite nanoparticles and the change of peak positions under different core-shell thickness and refractive index of different media. The results show that with the increase of the shell thickness, the extinction spectrum of the composite nanoparticles gradually forms two extinction peaks similar to the simple metal nanoparticles, and then gradually becomes an extinction peak with a broad FWHM. At The extinction peaks of the composite nanoparticles in different media environments all showed redshift with the increase of the dielectric constant. The effect of silver on the total extinction spectrum was stronger than that of gold, both as the core layer and the shell layer.