Fabrication of moth eye structures via charged nanoparticle lithography with size and density control

We have developed and demonstrated an effective method for fabricating the moth eye structures formed by charged nanoparticle lithography (cNPL). We attached high-density gold nanoparticles (Au NPs) to GaN without aggregation by making the surface of Au NPs negatively charged and GaN positively charged. Au NPs were effectively used as an etching mask, and the moth eye structures of GaN were formed by inductively coupled plasma reactive ion etching. The moth eye structures with various sizes and densities were fabricated by the cNPL, and the moth eye structures reduced the reflectance. The cNPL, as a simple technique with size and density control, will provide high potential to optical device applications.