Electrospray-assisted fabrication of uniform photonic balls

Abstract

Photonic balls have been fabricated (see Figure) by field-enhanced electrospray of an aqueous colloidal suspension. The polystyrene (PS) beads inside the suspension droplets self-organize into opaline balls while the solvent evaporates. The opaline balls are used as templates for inverse opaline photonic balls, and both types exhibit varying reflection colors depending on the diameter of the beads and the reflective index contrast.