Photonic crystals of core-shell colloidal particles

Abstract

We report on the fabrication and optical transmission studies of thin three-dimensional (3D) photonic crystals of high-dielectric ZnS-core and low-dielectric SiO 2 -shell colloidal particles.These samples were fabricated using a vertical controlled drying method. The spectral position and width of a stopgap depend on the core-to-shell ratio, in a manner consistent with numerical calculations. Both experiments and calculations show that the relative L-stopgap width in the case of high-index core low-index shell particles can be larger in comparison to the case of homogeneous particles of either material. The core-shell morphology gives additional control over the photonic stopgap characteristics. § Corresponding authors; electronic mails: K.P. Velikov@phys.uu.nl, A.vanBlaaderen@phys.uu.nl

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