Far-field optical properties of disordered dielectric nanoparticle arrays within T-matrix framework

The angular distribution of far-field light intensity scattered by a two-dimensional array of nanoparticles depends on the optical properties of individual nanoparticles and their spatial distribution. The latter factor affects the scattered far-field in a two-fold manner. One such effect is the modification of the multipole moments of each individual scatter as a consequence of multiple scattering of light between the nanoparticles. The other one is the distribution of phase of multipolar fields that interfere to form the far-field pattern, which originates from the spatial distribution of the nanoparticles. In this work, we utilize an effective medium model developed within the T-matrix framework to calculate the angle-resolved scattered far-field intensity of disordered arrays composed of high-index nanoparticles. We show that our model may be used to predict the optical spectra including both radiative (far-field interference) effects as well as the multiple scattering effects making it a computationally efficient and accurate approach to model nanoparticle arrays with positional disorder. We utilize the presented model to study the capability to engineer the scattering-to-absorption ratio as well as the scattering directionality via tailoring the spatial distribution of nanoparticles. Control over those properties is sought after in nanoparticle applications such as photovoltaics and affects the efficiency of dielectric metasurfaces.