Aerosol Impaction-Driven Assembly System for the Production of Uniform Nanoparticle Thin Films with Independently Tunable Thickness and Porosity

Thin films composed of nanoparticles are used in a variety of applications, from antireflective coatings in photovoltaic modules to antibacterial agents in textiles. In this work, we demonstrate an aerosol-impaction-based process for forming uniform thin films of controllable thickness and porosity on large-area substrates. Through a combination of scanning electron microscopy, Rutherford backscattering, and elliposometry, we demonstrate silicon nanoparticle films with independently tunable thicknesses between 50 nm and 3 μm and porosities between 67% and 95%. We further demonstrate the scalability of this process by forming films with <7% thickness nonuniformity and <1% porosity nonuniformity on 125-mm-diameter silicon substrates.