Broadband Antireflection Coatings Based on Low Surface Energy/Refractive Index Silica/Fluorinated Polymer Nanocomposites

We demonstrated the fabrication of broadband antireflection coatings (ARCs) comprising low-surface energy/refractive index (RI) silica/polymer nanocomposites by silica mineralization of layer-by-layer (LbL) assembled poly(2-(dimethylamino)ethyl methacrylate)-block-poly(2,2,3,3-tetrafluoropropyl methacrylate)/poly(L-glutamic acid) (PDMA-b-PTFP/PGA) multilayer films without any post-treatments. The introduction of the fluorinated polymer (PTFP segments) effectively lowered not only the RI of the as-fabricated coatings but also the surface energy of the constituted pore surface, which rendered the ARCs with high transmittance and durable AR performance by preventing the absorption and capillary condensation of moisture at ambient conditions. Moreover, the formation of nanosized PDMA-b-PTFP vesicles can render the ARCs exhibiting small pore size, which can improve their light transmittance. The coated substrate with an average transmittance over 97.0% was obtained at the visible wavelength region. The combination of LbL assembly and silica mineralization can warrant the preparation of conformal, intact coatings with good mechanical properties. This study demonstrated a novel concept on introducing low surface energy/RI materials for fabricating broadband, moisture-repellent ARCs.