Tailoring Patterned Visible-Light Scattering by Silicon Photonic Crystals

Abstract

Searching for the relationship between the nanostructure and optical properties has always been exciting the researchers in the field of optics (linear optics as well as non-linear optics), energy harvesting (anti-reflective Si solar cells, perovskite solar cells, ..., etc.), and industry (anti-reflection coating on car windows, sunglasses, etc.). In this work, we present an approach for nanostructuring the silicon substrate to silicon photonic crystals. By precisely controlling the etching time and etching path after using nanoimprint lithography, ordered arrays of inverted Si nanopyramids and Si nanopillars with good homogeneity, uniform surface roughness, high reproducibility of pattern transfer, and a controllable aspect ratio are prepared. Experimental investigation of the optical properties indicates that the reflections of these Si nanostructures are mainly determined by the aspect ratio as well as the period of nanostructures. Furthermore, we have experimentally observed visible-light scattering (V-LS) patterns on inverted Si nanopyramids and Si nanopillars, and their corresponding patterns can be precisely controlled by the patterned nanostructures. The V-LS pattern, background, and “ghost peaks” on the angle-resolved scattering results are caused by constructive interference, destructive interference, and the interference situation between both. This controllable nanopatterning on crystalline Si substrates with precisely tunable optical properties shows great potential for applications in many fields, for example, optics, electronics, and energy.

Continuous roller nanoimprinting: next generation lithography

“…In addition to LED, DOEs and diffractive waveguides, R-NIL can also be used to fabricate a range of other optical components, such as polarizers, 152 micro-lenses, 153 anti-reflective films, 154 scattering films, 155 and interference filters. 156 R-NIL is also widely applied in the fields of energy harvesting ( e.g.…”

“…R-NIL was used as a highly effective method for fabricating these waveguides with high precision and low cost, making them an attractive option for AR device manufacturers. 151 In addition to LED, DOEs and diffractive waveguides, R-NIL can also be used to fabricate a range of other optical components, such as polarizers, 152 micro-lenses, 153 anti-reflective films, 154 scattering films, 155 and interference filters. 156 R-NIL is also widely applied in the fields of energy harvesting (e.g.…”