Scalable Nanofabrication of T-Shape Nanopillars Based on Polystyrene/Polyphenylsilsequioxane Films Showing Broadband Antireflection and Super-omniphobicity

The ability to create antireflective super-omniphobic surfaces is important for various optoelectronic applications, which is still a challenge. The combination design of sub-wavelength nanoscale structures for antireflection and re-entrant structures for super-omniphobicity is an effective way to obtain super-omniphobicity and antireflection simultaneously. However, due to the inclination of droplets to strike to the bottom and the complicated craftsmanship, obtaining efficient nanoscale re-entrant super-omniphobic surfaces is difficult, which limits the compatibility of antireflection and super-omniphobicity. Herein, disordered nanoscale T-shape pillars are utilized to obtain the broadband antireflection, non-iridescence, and super-omniphobicity. A simple and repetitive method is reported for large-area scalable fabrication of disordered nanoscale T-shape pillars on glass based on a maskless phase separation lithographic approach. The kinetic roles of Laplace pressure, viscous force, and saturated vapor pressure in the super-omniphobicity are demonstrated by investigating the effect of feature size, interval, area fraction and pillar height of the T-shape nanopillars, liquid surface tension, viscosity, etc. The effects of feature size, interval, and height on the antireflection and the optical behavior on the T-shape nanopillars are also investigated. Although the cap of T-shape nanopillars could bring scattering loss when light touches on the cap range with a large incident angle, broadband antireflection is still obtained. As a demonstration, T-shape nanopillars exhibiting super-omniphobicity (static water contact angle of 160 ± 1.0° and ethyl alcohol contact angle of 162 ± 0.5°), high transparency (94%), broadband antireflection (347–780 nm), and non-iridescence are obtained. Our proposed method provides a simple, rapid, and low-cost process to explore the ability of nanoscale re-entrant structures for compatibility of broadband antireflection and super-omniphobicity, with promising practical application in self-cleaning optoelectronic surfaces.