纳米粒子形貌与表面等离子体激元关系

Relationship of Surface Plasmon Polaritons and Nanoparticles Morphology

通过调控纳米粒子表面形貌,研究了纳米粒子形貌与表面等离子体激元之间的关系.采用水相化学合成法制备出粗糙表面"花朵"形银纳米粒子.通过自组装形成单层阵列,并进一步组装成复合结构超材料.测试了其光学行为,并将实验结果与树枝形纳米粒子、光滑表面纳米粒子进行对比分析.结果表明:光滑表面纳米粒子不能出现超材料效应,当粗糙程度增加,纳米粒子呈类"花朵"形时,样品出现透射峰和平板聚焦行为,但强度不高;当粗糙程度继续增加,纳米粒子呈树枝状时,出现了较强的透射峰与平板聚焦行为.研究证实通过改变纳米粒子表面形貌,可以调控表面等离子体激元与入射光的相互作用,从而实现对光传播的操控.

The relationship of surface plasmon polaritons and morphology of nanoparticles was researched by tailoring the particle′s surface morphology.Roughened silver nanoparticle was prepared by aqueous chemical method and further fabricated into composite structured metamaterial,the optical behavior of as-prepared sample was measured then.The experimental results are contrasted with the one of dendrites and smooth-surface particles.The results show that metamaterials effect does not appear in smooth-surface particles,however,the peculiar effect appears in flower-like particles and dendritic particles with lower and higher intensity,respectively.By altering the structure of a particle′s surface,the properties of surface plasmons can be significantly changed,and the manipulation on light propagation can also be realized.