Laboratoire de Chimie, ENS Lyon, CNRS, Université Claude Bernard Lyon 1, Université de Lyon, UMR 5182, 46 allée d'ltalie, 69364 Lyon, France.
Nanotechnology. 2012 Apr 13;23(14):145707. doi: 10.1088/0957-4484/23/14/145707. Epub 2012 Mar 21.
A great number of works focus their interest on the study of gold nanoparticle plasmonic properties. Among those, sharp nanostructures appear to exhibit the more interesting features for further developments. In this paper, a complete study on bipyramidal-like gold nanostructures is presented. The nano-objects are prepared in high yield using an original method. This chemical process enables a precise control of the shape and the size of the particles. The specific photophysical properties of gold bipyramids in suspension are ripened by recording the plasmonic response of single and isolated objects. Resulting extinction spectra are precisely correlated to their geometrical structure by mean of electron tomography at the single-particle level. The interplay between the geometrical structure and the optical properties of twisted gold bipyramids is further discussed on the basis of numerical calculations. The influence of several parameters is explored such as the structural aspect ratio or the tip truncation. In the case of an incident excitation polarized along the particle long axis, this study shows how the plasmon resonance position can be sensitive to these parameters and how it can then be efficiently tuned on a large wavelength range.
大量的研究工作都集中在对金纳米颗粒等离子体特性的研究上。在这些研究中，尖锐的纳米结构似乎表现出更有趣的特性，值得进一步开发。本文全面研究了类双锥金纳米结构。纳米物体是使用原创方法高产率制备的。这种化学过程能够精确控制颗粒的形状和尺寸。通过记录单个和孤立物体的等离子体响应，使悬浮金双锥体的特定光物理性质成熟。通过在单粒子水平上进行电子断层扫描，将消光谱精确地与其几何结构相关联。基于数值计算，进一步讨论了扭曲金双锥体的几何结构和光学性质之间的相互作用。研究了几个参数的影响，例如结构纵横比或尖端截断。在沿粒子长轴的入射激发的情况下，这项研究表明等离子体共振位置如何对这些参数敏感，以及如何在大波长范围内有效地进行调谐。
