High-performance Nanopillar Arrays with Anti-reflective and Anti-bacterial Properties

The reflection of light at interfaces limits the performance of optical components. An anti-reflection (AR) coating layer is often applied to improve the optical transmittance. Besides the commonly used singleor multi-layer coatings reducing the reflection, subwavelength nanostructures have gained more attention as an effective AR feature. A wide choice of materials can be nanostructured without adding a layer of an additional material, resulting in better mechanical and thermal stability [1]. There are also reports on antbacterial (AB) properties for nanostructures, such as the nanopillars on the wings of a Cicada species [2] or nanoprotrusions in a black silicon substrate serving as a biomimetic example [3]. Here, we show both AR and AB properties combined in a nanopillar geometry and discuss the implications of these features on biomimetic nanostructured surfaces for optical and biomedical applications.