Multilevel Spherical Photonic Crystals with Controllable Structures and Structure-Enhanced Functionalities

Abstract

Spherical photonic crystals (SPCs) with tailorable multiscale structure, versatile surface morphology, and controllable optical properties of both photonic stop band (PSB) and surface plasmon resonance (SPR), have been fabricated using a robust and facile method. The fabricated SPCs consist of well-spaced gold nanocrystals (AuNCs) (3rd-tier) anchored on silica nanopatterns (2nd-tier) confined in microspherical templates (1st-tier). Droplet microfluidics is used to produce microdroplets containing silica nanoparticles (SiO2NPs) which assemble to form two-tier SPCs. Subsequently, three-tier SPCs are obtained by thermal dewetting and evaporation of metal films deposited on the two-tier SPCs, wi..