Fabrication of Broadband Antireflective Plasmonic\nGold Nanocone Arrays on Flexible Polymer Films

Abstract

Flexible\nbroadband antireflective and light-absorbing nanostructured\ngold thin films are fabricated by gold vapor deposition onto Teflon\nfilms modified with nanocone arrays. The nanostructures are created\nby the oxygen plasma etching of polystyrene bead monolayers on Teflon\nsurfaces. The periodicity and height of the nanocone arrays are controlled\nby the bead diameter and the overall etching time. The gold nanocone\narrays exhibit a reflectivity of less than 1% over a wide spectral\nrange (450–900 nm) and a wide range of incident angles (0–70°);\nthis unique optical response is attributed to a combination of diffractive\nscattering loss and localized plasmonic absorption. In addition to\nnanocones, periodic nanostructures of nanocups, nanopyramids, and\nnanocavities can be created by the plasma etching of colloidal bilayers.\nThis fabrication method can be used to create flexible nanocone-structured\ngold thin films over large surface areas (cm²) and should\nbe rapidly incorporated into new technological applications that require\nwide-angle and broadband antireflective coatings.