Using Highly Accurate 3D Nanometrology to Model the Optical Properties of Highly Irregular Nanoparticles: A Powerful Tool for Rational Design of Plasmonic Devices

Abstract

The realization of materials at the nanometer scale creates new challenges for quantitative characterization and modeling as many physical and chemical properties at the nanoscale are highly size and shape-dependent. In particular, the accurate nanometrological characterization of noble metal nanoparticles (NPs) is crucial for understanding their optical response that is determined by the collective excitation of conduction electrons, known as localized surface plasmons. Its manipulation gives place to a variety of applications in ultrasensitive spectroscopies, photonics, improved photovoltaics, imaging, and cancer therapy. Here we show that by combining electron tomography with electrodynamic simulations an accurate optical model of a highly irregular gold NP synthesized by chemical methods could be achieved. This constitutes a novel and rigorous tool for understanding the plasmonic properties of real three-dimensional nano-objects.

Structural study of near-field ablation close to plasmon-resonant nanotriangles

“…In fact, it has been shown that the exact shape of the gold triangle plays an important role in the distribution of the resulting near-field. 24 Furthermore, our simulations suggest that the optical environment (in this case especially the thickness of the SiO 2 layer) is also of great importance for the near-field distribution. All simulations have been carried out with the commercially available software package FDTD Solutions (Lumerical Solutions, Inc.) […”

“…In fact, it also suffered from a less detailed input of the boundary conditions (concave particle walls, rounding of the edges, and dielectric constant of the substrate). The importance of an exact modeling of a given nanostructure for the outcome of calculations has recently been shown by Perassi et al 24 Furthermore, the experimental premises in Refs. 7 and 9 are not exactly the same.…”

Plasmonic Properties of Welded Metal Nanoparticles

“…3D models based on the numerical methods such as the discrete dipole approximation (DDA), the finite difference time domain (FDTD) method, and FEM have been used to simulate the near-field intensity distribution of metallic nanostructures with arbitrary geometries by solving the Maxwell's equations numerically [45][46][47][48]. Compared with other numerical methods, 3D-FEM shows high accuracy for modeling irregular structures and simulating fine elements within large domains.…”

Reduced-dose and high-speed acquisition strategies for multi-dimensional electron microscopy

“…ET based on these imaging modes is nowadays often performed in an automated or semi-automated manner and is routinely employed for the study of morphology and distribution of features in 3D (e.g. [4][5][6][7]). …”