Broadband and crack-free antireflection coatings by self-assembled moth eye patterns

ACS Appl Mater Interfaces. 2014 Apr 23;6(8):5827-34. doi: 10.1021/am500687f. Epub 2014 Apr 9.

Abstract

We report broadband and quasi-omnidirectional antireflective (AR) structures inspired to the nipple arrays of moth eyes. These nanocoatings, based on thin elastomeric films, are prepared by simple self-assembly processing of a co-polymer specifically designed to this purpose, and PDMS replica molding. Typically, their surface is covered by a compact distribution of hemispherical nanodomes of about 250 nm in diameter and about 100 nm in height. When these novel nanostructures are applied on a single glass surface, a maximum of 2% transmission enhancement (equivalent to a 50% reduction of the reflected component) towards wavelengths ranging from visible to near IR region is obtained. A considerable AR power is observed also at a wide range of incident angles ranging from normal to 50°. These properties could be attributed to an optimized graded refractive index profile resulting from the randomly distributed and close-packed nanodomes. Moreover, thanks to their elastomeric nature, these crack-free films can be easily applied on glass, as stickers, and periodically replaced, thus offering the possibility of easy dirt removal from an optical device.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Eye / chemistry
  • Materials Testing
  • Moths
  • Nanostructures / chemistry*
  • Optical Devices
  • Polymers / chemical synthesis
  • Polymers / chemistry*
  • Refractometry
  • Surface Properties

Substances

  • Polymers