The method of structural study of aggregates of plasmonic gold nanoparticles by UV/visible spectroscopy

Abstract

The problem of obtaining nanostructured silicate glasses containing silver or gold particles and their agglomerates in recent years is one of the topical directions of photonics. The main advantage of gold in glass nanoparticles is the localized surface plasmon resonance (SPR). Due to their unique optical properties, these objects are used for optoelectronics devices as nanoantennas and biosensors. The position and shape of the SPR can be tuned to the desired wavelength in the visible and near infrared regions, varying the size, interparticle distances, and the dielectric medium in which the particles are located. The aim of this work is to analyze the optical spectra of gold nanoparticles implanted in silicate glass by irradiation with an ultraviolet laser and subsequent purification, and to determine of interparticle distances and particle sizes from the SPR spectra. For the theoretical description of optical spectra, the T-matrix approach was used, which allows to model the scattering of an electromagnetic wave by agglomerates of spheres, which correspond to studied agglomerates of nanoparticles. The application of this approach allowed to determine the structural parameters of aggregates, including averaged size of particles, average interparticle distance, statistical distributions over sizes and interparticle distances.