title: Single-Step Soft-Imprinted Large-Area Nanopatterned Antireflection Coating.
abstract: We demonstrate an effective nanopatterned antireflection coating on glass that is based on sol-gel chemistry and large-area substrate-conformal soft-imprint technology. The printed 120 nm tall silica nanocylinders with a diameter of 245 nm in a square array with 325 nm pitch form an effective-index (n = 1.20) antireflection coating that reduces the double-sided reflection from a borosilicate glass slide from 7.35% to 0.57% (averaged over the visible spectral range) with a minimum reflectance <0.05% at 590 nm. The nanoglass coating is made using a simple process involving only spin-coating and an imprint step, without vacuum technology or annealing required. The refractive index of the nanoglass layers can be tailored over a broad range by controlling the geometry (1.002 < n < 1.44 in theory), covering a wide range that is not achievable with natural materials. We demonstrate that the nanoglass coating effectively eliminates glare from smart-phone display windows and significantly improves the efficiency of glass-encapsulated solar cells. These features, that are achieved over an angular range as wide as ±50°, together with strong hydrophobicity and mechanical durability, make nanoglass coatings a promising technology to improve the functionality of optoelectronic devices based on glass encapsulation.
authors.affiliation: †Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Jorik
authors.initials: J
authors.lastname: van de Groep
authors.affiliation: †Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.|‡Energy Research Center of The Netherlands ECN, Westerduinweg 3, 1755 LE Petten, The Netherlands.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Spinelli
authors.affiliation: †Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Polman
keywords: Antireflection coating; hydrophobicity; nanoimprint lithography; nanopattern