Optical Properties of a Monolayer of Metallic Nanoparticles in a Thin-Film Stack

Metallic nanoparticles exhibit a plasmonic resonance : they strongly absorb or scatter light around the resonance wavelength. One of their applications is the generation of structural colors [1].<br/>This work aims at a better understanding of the optical properties of disordered assemblies of metallic nanoparticles embedded in a thin film stack, using both experimental and theoretical approaches. Experimentally, monolayers of silver nanoparticles are grown by magnetron sputtering deposition with in-situ monitoring of the nanoparticles growth [2] and their absorption spectra are measured by spectrophotometry. Theoretically, we use analytical models [3] and numerical methods [4,5] to investigate how optical properties are affected by the electromagnetic interaction between the particles and their environment (neighboring particles and interfaces).<br/><br/><b>References: </b><br/>[1] A. Kristensen, J.K.W. Yang, S.I. Bozhevolnyi, S. Link, P. Nordlander, N.J. Halas, N.A. Mortensen, <i>Plasmonic colour generation</i>, Nature Reviews Materials, <b>2</b> (2016).<br/>[2] Q. Hérault, <i>Mécanismes de croissance des couches minces d’argent par pulvérisation cathodique magnétron</i>, phd thesis (2019)<br/>[3] A. Reyes-Coronado, G. Morales-Luna, O. Vazquez-Estrada, A. Garcia-Valenzuela, R. G. Barrera, <i>Analytical modeling of optical reflectivity of random plasmonic nano-monolayers</i>, Optics Express, <b>26</b>, 12660 (2018)<br/>[4] M. Bertrand, A. Devilez, J. P. Hugonin, P. Lalanne, K. Vynck<i>, Global polarizability matrix method for efficient modeling of light scattering by dense ensembles of non-spherical particles in stratified media</i>, J Opt Soc Am A, <b>37</b>, 70 (2020)<br/>[5] R. Lazzari, I. Simonsen, <i>GranFilm: a software for calculating thin-layer dielectric properties and Fresnel coefficients</i>, Thin Solid Films, <b>419</b>, 124 (2002)