Index-Matched Composite Colloidal Crystals of Core-shell Particles with Structural Colors and Optical Transparency

Abstract

We prepared composite colloidal crystal films of core–shell nanospheres in an index-matched polystyrene matrix. Therefore, we demonstrate strong reflection colors in a thick colloidal film keeping high optical transparency. Furthermore, with no deterioration of light transmission in our index-matched composite colloidal crystals, bicolored reflective films were also successfully prepared by stacking two different colloidal crystal films. Finally, by introducing photopolymerizable resin inside colloidal crystals, we patterned composite photonic crystals through selective photopolymerization and repeated photopatterning process for multicolored films. These films may potentially be useful in reflective displays, encryption, and optical identification.