One-step Maskless Fabrication and Optical Characterization of Silicon Surfaces with Antireflective Properties and a White Color Appearance

Abstract

We report a simple one-step maskless fabrication of inverted pyramids on silicon wafers by reactive ion etching. The fabricated surface structures exhibit excellent anti-reflective properties: The total reflectance of the nano inverted pyramids fabricated by our method can be as low as 12% without any anti-reflective layers, and down to only 0.33% with a silicon nitride coating. The results from angle resolved scattering measurements indicate that the existence of triple reflections is responsible for the reduced reflectance. The surfaces with the nano inverted pyramids also exhibit a distinct milky white color.

Fabrication of Large Area Broadband and Omnidirectional Antireflective Transparent Foils by Roll‐to‐Roll Extrusion Coating

“…The classical moth‐eye AR structure consists of hexagonally arranged tapered nanopillars . The AR effect has also been reported for random structures, most notably for the “black Si” or “nanograss” structures, which are fabricated by a maskless reactive ion‐etching process; however these structures exhibit light scattering in the visible spectrum, rendering polymer surfaces replicated from black silicon less transparent . The moth‐eye effect is well understood in terms of the so‐called effective medium theory which employs a graded index matching principle for a tapered subwavelength 2D surface structure …”

Bioinspired Microstructured Polymer Surfaces with Antireflective Properties

“…The super black surface was prepared by the chemical etching of an electroless-deposited nickel-phosphorus alloy, which reflected <0.4% of light in the visible region [ 3 ]. Since then, scientists have been competing in a race to produce the blackest material, with some of the most successful examples being black silicon [ 4 , 5 , 6 ], Vantablack, i.e., Vertically-Aligned carbon NanoTube Arrays [ 7 ], dark chameleon dimers based on gold nanoparticles [ 8 ], and a more recent carbon nanotube-based material developed at MIT [ 9 ]. Although extremely valuable, these solutions usually require complicated fabrication procedures and post-application treatments, as they are based on nanoparticles and/or nanostructures.…”