Substrate-mediated antireflective properties of silicon nanoparticle array

In this work, we study optical properties of all dielectric metasurfaces on the top of high-index substrate. We perform numerical simulations of spherical nanoparticle arrays for different permittivities of the substrate, and propose a simple model with separate contributions from nanoparticle arrays and bare substrate into the total reflection, which fully agrees with numerical results. For the single nanoparticle in homogeneous environment, zero backscattering, or Kerker effect, is observed when electric and magnetic moments are in phase. In contrast, the reflection suppression from nanoparticle-coated substrate occurs when the out of-phase condition is satisfied, i.e. for the wavelength between the resonances of electric and magnetic dipole moments. The influence of high-index substrate is crucial for designing optical metasurfaces and photovoltaic elements with nanoparticle-enhanced light trapping.