Design of Artificial Hollow Moth-Eye Structures Using Anodic Nanocones for High-Performance Optics

Abstract

We demonstrated an innovative approach for the fabrication of self-organized, hollow-to-solid nanocone arrays, using a decoupling two-step anodization of an Al/Ta interlayer on a substrate. The porosity of the hollow nanostructures was tunable by the deposited thickness of Ta film. We also employed subwavelength nanocone arrays as Moth-eye structures for high-performance antireflection coatings. These oxide nanostructures greatly suppressed reflectance over a large range of wavelengths and angles of incidence and displayed a good mechanical stability. When a corresponding porosity was designed, these nanostructures could be applied to various substrates for an effective antireflection coating. In addition, we were able to customize antireflection coatings for various types of substrates or materials of interest based on the suitable coating of initial Ta thickness.